JPH0440395B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photochromic photosensitive material, and in particular to a photochromic photosensitive material that has a high color retention rate even after long-term storage and has low temperature dependence. A rewritable image display material or optical recording material using a dispersed photochromic material in which a spiropyran compound is dispersed and dissolved in a binder such as a polymer compound is known. However, the biggest problem with such dispersed materials is the stability of their recording state. That is, even if the colored spiropyran compound is stored in a shielded state from light, it undergoes a decoloring reaction due to thermal action, resulting in a decrease in the contrast of the recorded state. Various methods have been proposed to improve the stability of this recording state. As one of them,
Attempts have been made to bond a spiropyran compound as a side chain to the main chain of a polymer compound to increase the stability of the coloring state. For example, the following structure () The N or 8' position of the indoline spiropyran having the basic skeleton shown in (for example, J. Verborgt, G.
Smets; J.POlym, Sci.: Polym.Chem.Ed., 12
2511 (1974)) or the following structural formula () The 5th or 8' position of the thiazoline spiropyran with the basic skeleton shown in (e.g., G.Smets, Pure
APPl.Chem, 30 , 1 (1972)), there is a method of bonding to the main chain of a polymer compound through an ester bond or the like. However, most of the photochromic substances obtained by such a method discolor at room temperature faster than the dispersion type materials, and even the photochromic substances, which are more stable than the dispersion type materials at room temperature, lose their color for several tens of minutes. It has been shown that the dark color developed decreases by half within a certain period of time, and it cannot be said that the storage stability is sufficient. The reason for the low stability of such a colored state is that when spiropyran is bonded to the polymer main chain at each of the above positions, the effect of steric hindrance that suppresses the intramolecular rotation that occurs during the decolorization reaction of spiropyran is small. This is thought to be due to the In view of the above, the present inventors conducted extensive research and found that the coloring state could be improved by using benzothiazoline spiropyran, which itself has a high coloring state stability, and by bonding it to the polymer main chain at the 3' position. A photochromic photosensitive material with high storage stability could be obtained. That is, the present invention relates to a photochromic photosensitive material comprising a layer of a polymer compound containing a monomer unit represented by the following general formula () as a copolymer component. (In the formula, R ₁ is an alkyl group having 1 to 10 carbon atoms, R ₂ is an alkoxy group having 1 to 5 carbon atoms, and 1 carbon number is
~5 alkyl group, halogen atom or cyano group,
R ₃ represents a halogen atom, an alkyl group having 1 to 5 carbon atoms, a nitro group, or a cyano group; R ₄ represents a divalent hydrocarbon group having 1 to 5 carbon atoms; and R ₅ represents a hydrogen atom or a methyl group. ) In the photosensitive material of the present invention, the amount of monomer units represented by the general formula () contained in the polymer compound as a copolymerization component is in the range of 3 to 50 mol%, preferably 5 to 20 mol%. can do. Note that if it is less than 3 mol %, the photochromic ability will not be sufficient, and if it exceeds 50 mol %, it will be difficult to obtain a polymer compound. Other copolymerization components of the polymer compound in the present invention include acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, sterene,
Monomers such as vinyl acetate and acrylonitrile can be mentioned. Further, when the polymer compound in the present invention contains two or more of the other copolymer components in addition to the monomer units represented by the general formula (), one of the copolymer components may include an acid component, e.g. It is preferable that acrylic acid or methacrylic acid is present in an amount of 5 mol % or more based on the copolymerized components of the two or more types. The polymer compound in the present invention includes methanol,
Alcohols such as ethanol and isopropyl alcohol, ketones such as acetone, methiethyl ketone and cyclohexanone, ethers such as ethyl ether, dioxane and tetrahydrofuran, esters such as ethyl acetate and n-butyl acetate, as well as benzene, toluene and xylene. , n-hexane, cyclohexane, acetonitrile, dimethylformamide, dimethylsulfoxide, chloroform, and mixed solvents thereof. In order to use this polymer compound as a photochromic photosensitive material, it can be used by dissolving the polymer compound in the above-mentioned solvent, coating it on a film forming area or support, and drying it. Examples of the support include polyethylene terephthalate, cellulose acetate, polycarbonate, ordinary paper, baryta paper, glass, metal, and the like. The polymer compound in the present invention can be obtained by copolymerizing a monomer represented by the following general formula () and the other copolymerization components. (In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ have the same meanings as above.) The monomer represented by the general formula () can be synthesized as follows. First, 2-chloromethyl-benzothiazoline () was synthesized from aminothiophenol and chloroacetyl chloride according to the method of R. Guglielmetti et al. (see Helv. Chim. Acta, 55 , 1782 (1972)). From now on, the following scheme will be followed. (i) 2-chloromethyl-benzothiazoline () is added to a solution of metallic sodium dissolved in HOR ₄ OH (R ₄ has the same meaning as above). (ii) The obtained compound of formula () and the compound

[Formula] (R ₁ has the same meaning as above) is reacted. (iii) Compounding the reaction product of formula () in the presence of a promoter in a solvent

[Formula] (R ₂ has the same meaning as above) to obtain a compound of formula (). (iv) The compound of formula () is dissolved in a solvent and the compound is dissolved in the presence of a catalyst.

[Formula] (R ₅ has the same meaning as above) is removed and reacted,
Compound ()′ is obtained. This compound ()' corresponds to the case where R ₃ is a hydrogen atom in the general formula (). In the above (ii), the compound of general formula () is substituted for the compound of formula () by the following formula ()' (wherein R ₅ has the same meaning as before). The compounds of formulas (), ()' and ()' are new substances. Synthesis examples of these new substances are shown below. (a) 2-hydroxyethoxymethylbenzothiazole (in the above formula (), R ₄ is -CH ₂ -
Compounds that are CH ₂ - group): Add 44 g of 2-chloromethyl-benzothiazoline to a solution of 8.00 g of sodium metal in 100 c.c. of ethylene glycol. The temperature of the reaction mixture was raised to 90°C and the mixture was reacted for 2 hours, then poured into water and extracted with chloroform.
Next, wash with water. Then, it is dried over anhydrous magnesium sulfate, the solvent is removed, and then purified by vacuum distillation. 25.6 g of 2-hydroxyethoxymethylbenzothiazole are obtained. Yield 51%, boiling point
168-180℃ (2mmHg). (b) 2-hydroxyethoxymethyl-5-nitrobenzothylazole (in the above formula ()',
Compounds in which R ₃ is a nitro group and R ₄ is a -CH ₂ CH ₂ - group): Concentrated sulfuric acid (92 c.c.) was added to 2-hydroxyethoxymethyl bezothiazole (90 g) under ice cooling, and the temperature When the temperature drops to 20℃, add concentrated sulfuric acid (72c.c.)
and fuming sulfuric acid (72 c.c.) at a temperature of 30
Add so that the temperature does not exceed ℃. After the addition is complete, the reaction mixture is poured into a large amount of water, and the resulting crystals are filtered. 2-hydroxyethoxymethyl-
67 g of 5-nitrobenzothiazole are obtained. Yield: 57%. (c) 2-hydroxyethoxymethyl-5-chlorobenzothiazole (a compound in which the above formula ()' is a chlorine atom and R ₄ is a _-CH2 - _CH2- group): 2-hydroxyethoxymethyl-5-nitro Benzothiazole (30g) in ethanol (150g)
cc), tin (30g) and concentrated hydrochloric acid (300g).
cc) and reacted at 30℃ for 3 hours,
Neutralized with NaOH, extracted with benzene, 2-
25 g of hydroxyethoxymethyl-5-aminobenzothiazole are obtained. (Yield: 94%). Concentrated hydrochloric acid (40 c.c.) was added to this 2-hydroxyethoxymethyl-5-aminobenzothiazole (25 g), and NaNO ₂ (8.3 g) was added while cooling with ice.
Once the crystals have dissolved, add CuCl ₂ (37 g copper sulfate,
9.71g NaCl, 7.90g _NaHSO3 and 5.20g NaOH
Add concentrated hydrochloric acid solution (synthesized from ) and incubate at 30℃ for 1.5 hours.
After reacting at 60°C for 30 minutes, the mixture is extracted with chloroform to obtain 2-hydroxyethoxymethyl-5-chlorpenzothiazole. The polymer compound of the present invention can be obtained by copolymerizing the monomer of the general formula () with the other copolymerization component by a conventional method. For example, if the other copolymerization component is methacrylic In the case of acid (MAA) and/or methyl methacrylate (MMA), the copolymerization reaction is carried out in a solvent such as dimethylformamide (DMF) in the presence of an initiator such as azobisisobutyronitrile (AIBN). be able to. The photosensitive material of the present invention is colorless or lightly colored in a normal state, but when irradiated with ultraviolet light, it becomes strongly colored, and the stability of this colored state is excellent, and the temperature dependence of this stability is small. The photosensitive material of the present invention having such characteristics can be used in a wide range of fields, such as various recording and storage materials replacing silver salt photosensitive materials, copying materials, photoreceptors for printing, recording materials for cathode ray tubes, and photosensitive materials for lasers. It can be used as a variety of recording materials such as photosensitive materials for holography, photosensitive materials for phototypesetting, etc. Also, optical filter,
Display materials, masking materials, light meters,
It can be used as a material for decoration. The hue or tone of the color can be varied depending on the monomer unit of the general formula () and the type of copolymer component. Next, the present invention will be described in more detail with reference to examples. Example 3'-Acryloxyexy-8'methoxy-3-methyl-6'-nitrospiro [2H-1-penzopyran-2,2-benzothiazoline] (hereinafter referred to as
Synthesis of TAENM) 2- obtained by synthesis according to the procedure described in section (a) above
After sealing hydroxyethoxymethylbenzothiazole (15.92 g) and methyl p-toluenesulfonate (17.00 g), they were kept at 100°C and reacted for 30 minutes, then washed with acetone and ethanol/
Recrystallize with acetone mixed solvent to obtain 3-methyl-
20.20 g of 2-hydroxyethoxymethylbenzothiazole tosylate (A) was obtained. Yield: 67%; melting point
110℃. Benzothiazole tosylate of (A) above (12.00
g), 3-methoxy-5-nitrosalicyl aldehyde (6.20 g), and piperidine (2.70 g) are added to ethanol and refluxed for 30 minutes to obtain a precipitate. After cooling, it was recrystallized with a mixed solvent of ethanol/chloroform to give 9.80 g of 3'-hydroxyethoxy-8'-methoxy-3-methyl-6'-nitrospiro [2H-1-benzopyran-2,2-benzothiazoline]. I got (B). The spirobenzopyran benzothiazoline (6.60 g) of (B) above was dissolved in anhydrous benzene, triethylamine (2.23 g) was added, and acrylic acid chloride (2.00 g) was added dropwise for 30 minutes. After finishing this dripping,
The reaction mixture was stirred for 30 minutes, washed thoroughly with water, dried over anhydrous magtisium sulfate, removed by elution, and recrystallized with a benzene/ether mixed solvent to obtain 7.11 g of TAENM. Yield: 95%; melting point: 152°C. The results of the TAENM spectra and their assignments were as follows. ¹ H-NMR δ3.04 (3H, S); N-methyl group; δ3.76 (3H, S): O-methyl group; δ4.20 (25, H) δ44.0 (2H, m) ethoxy group ; δ6.70-7.45 (3H, m): Acrylic group; δ7.58-8.30 (4H, m): Hydrogen at 4, 5, 6 and 7 positions; δ8.56 (d, J = 2.5Hz1H): 7 Hydrogen at position ′; δ6.88 (1H, S): Hydrogen at position 4′; δ8.64 (1H, d, J=2.5Hz): Hydrogen at position 5′; (δ is TMS standard, S is - line, d indicates doublet and m indicates multiplet) IR: 1730, 1520, 1340cm ^-1 UV: λ ^DMF _nax 341nm (ε=8400) Synthesis of polymer compounds (1) TAENM-MMA copolymer: TAEM (1.00g) and MMA (7.00g)
After stirring in DMF (60c.c.) for 30 minutes at an external bath temperature of 60℃ while bubbling nitrogen gas,
AIBN (40 mg) was added and reacted at 60°C for 8.5 hours. After the reaction is complete, the reaction mixture is poured into methanol containing a small amount of hydroquinone to precipitate the product. After filtering this precipitate, it was dissolved in acetone and poured into methanol to precipitate. After repeating this reprecipitation operation three times, vacuum drying was performed at 80° C. all day and night to obtain 3.84 g of a copolymer (sample P-(2-MMA)). Yield: 48%;
TAENM content: 2.4 mol%. Similarly, two types of copolymer samples with different TAENM contents (P-(1-
MMA)) and (P-(10-MMA)) were obtained. (2) TAENM-MAA copolymer; TAENM (600mg) and MAA (4.2g)
Dissolve in DMF (15 c.c.) and 8 ml under the same conditions as in (1) above.
Allowed time to react. The reaction mixture is then poured into ether containing a small amount of hydroquinone to precipitate the product. This precipitate was dissolved in methanol and poured into ether for precipitation. After repeating this reprecipitation operation twice, vacuum drying was performed for 2 days, and 3.73g
A copolymer of (sample symbol P-(2-MAA)) was obtained.
Yield: 78%; TAENM content: 1.9 mol%. In the same manner, a copolymer with a TAENM content of 10.3 mol% (sample code P-(10-MMA)) was obtained. (3) TAENM-MMA-MAA copolymer: MAA
(1g), MMA (1g) and TAENM (1.3g)
Dissolve in DMF and heat at 70℃ in the same manner as in (1) above.
After reacting for 8 hours, the reaction solution was poured into ether containing a small amount of hydroquinone, and the precipitated product was filtered, dissolved in a methanol-acetone mixed solvent, and poured into ether to cause precipitation. After repeating this reprecipitation operation twice, vacuum drying was performed for one day and night to obtain 2.2 g of a copolymer (sample code P-12 (MMA-MAA)). Yield: 67%;
TAENM content: 12.0 mol%; MMA content:
46.9 mol%; MAA content: 41.2 mol%. In the same manner, two types of copolymer samples having different compositions (P-(5-MMA-MAA)) and (P-(15-MMA-MAA)) were obtained. The composition and yield of each of the above copolymer samples were
They are summarized in the table.

[Table] Preparation of photochromic photosensitive material For photochromic property evaluation, 1 part by weight of the copolymer sample was dissolved in 10 parts by weight of solvent, and this solution was coated on a quartz glass plate (vertical x
(width x thickness = 30 x 30 x 2 mm), and adjust the rotation speed of the spinner coater to reduce the film thickness to approx.
The thickness was set to 1 μm. A mixed solvent of acetone:cyclohexanone=1:1 was used as the solvent. However, in the case of a copolymer with a high MMA content, methanol or DMF was used as the solvent. In this way, samples of the photochromic photosensitive material of the present invention were obtained. First, the storage stability of these samples in a dark place at 30° C. in a color-developed state by ultraviolet irradiation was measured as follows. The conditions for ultraviolet light irradiation were as follows: Using a 500W ultra-high pressure mercury lamp (manufactured by Ushio Electric Co., Ltd.), it was passed through a glass filter (IRA-25S and UV-D36C, manufactured by Toshiba Corporation).
A bright line around 360 nm was selectively irradiated. A Hitachi 320 self-recording spectrophotometer was used to measure the absorbance of the colored sample. The storage stability of the color development state was expressed by the following color retention rate. Color retention rate = A/A ₀ However, A ₀ = Color retention rate of the color sample at the initial stage of storage.
Absorbance at 590 nm A = Absorbance at 590 nm of the colored sample after storage for each time A/A ₀ The results of determining the absorbance against the storage time are shown in Table 3 and FIG. In FIG. 1, the storage stability of the coloring state of samples No. 1, 2, and 3 of this example is shown by curves 1, 2, and 3, respectively. As a comparative example, a sample of a dispersed photochromic material was prepared using the following formula: 3'-isobutyroxyethoxy-8'-methoxy-3-methyl-6'-nitrospiro [2H-1-benzopyran-2,2'-benzothiazoline] (hereinafter referred to as
A model compound (referred to as TAENM') and polymethyl methacrylate (PMMA) were used in the mixing ratios shown in Table 2. The sample preparation method was the same as described above.

[Table] The model compound TAENM' was synthesized as follows. That is, the spirobenzopyran benzothiazoline (1.00 g) of the above (B) was dissolved in anhydrous benzene, triethylamine (340 mg) was added,
Isobutyryl chloride (300 mg) was mixed with benzene (10
cc) and added dropwise over 30 minutes. After the addition, the reaction mixture was stirred for 30 minutes, washed thoroughly with water, dried over anhydrous magnesium sulfate, and after removing the solvent, recrystallized with a benzene-ether mixed solvent to obtain 1.07 g of TAENM'. Ta. Yield: 91%;
Melting point: 144-145°C For each sample of the comparative example, storage stability in a dark place at 30°C in a colored state by ultraviolet light irradiation was measured in the same manner as above. The results are shown in Table 3 and Figure 1. In Figure 1, the storage stability of Comparative Example Nos. 1', 2' and 3' is shown by curves 1', 2' and 3' respectively.
Indicated by 3′.

[Table] Photochromic photosensitive material of the present invention, No.
Samples 1 to 3 are the corresponding comparative examples No.1' to
It can be seen that the color preservation rate of sample No. 3 is higher than that of sample No. 3', except that it is slightly lower than the corresponding sample No. 3' during the storage period of 200 minutes or less. Sample No. 3 was also found after about 200 minutes.
It can be seen that the color retention rate is higher than that of No. 3′, and the longer it is stored, the more advantageous it becomes. In addition, samples No. 4, 6, and 7 containing an acid component (MAA) had a higher color retention rate than any of the samples No. 1' to 3' of the comparative example, and in particular, No. 6 ( P-(12-MMA-
MAA)) and No. 7 (P-(10-MAA)),
It can be seen that the color preservation rate is improved by about two orders of magnitude compared to the comparative sample No. 3' (10/PMMA). Next, regarding samples No. 3 and No. 4 of this example,
In order to investigate the storage stability of color schemes at high temperatures, 30℃,
The color retention rate in the dark at 50°C and 70°C was measured in the same manner as above. As a comparative example, the sample No. 3' was used. These results are shown in Figure 2 (dark place at 30°C), Figure 3 (dark place at 50°C), and Figure 4 (dark place at 70°C).
A graph showing the relationship between the natural logarithm of color retention rate (lnA/A ₀ ) and storage time is shown in FIG. In FIGS. 2 to 4, curves 3 and 4 are shown for samples No. 3 and No. 4 of the present example, and curve 3' is shown for sample No. 3' of the comparative example. As is clear from the graphs in Figures 2 to 4,
Photochromic photosensitive material No. 3 of the present invention
Sample No. 4 and Comparative Example No. 4 were heated at higher temperatures.
The storage stability of the coloring state is significantly better than that of the 3' sample. The small temperature dependence of the storage stability of the coloring state can be considered an excellent feature, considering that in practical use the device may be exposed to temperatures of several tens of degrees Celsius. As described above, the photochromic photosensitive material of the present invention has a higher color retention rate during long-term storage than the corresponding dispersion type photochromic photosensitive material, and the temperature dependence of the color retention rate is small.

[Brief explanation of drawings]

Figures 1 and 2 show the color development of each photochromic photosensitive material of Examples and Comparative Examples of the present invention in a dark place at 30°C, Figure 3 in a dark place at 50°C, and Figure 4 in a dark place at 70°C. It is a graph showing the storage stability of the state.

Claims (1)

[Scope of Claims] 1. A photochromic photosensitive material comprising a layer of a polymer compound containing a monomer unit represented by the following general formula as a copolymer component. (In the formula, R ₁ is an alkyl group having 1 to 10 carbon atoms, R ₂ is an alkoxy group having 1 to 5 carbon atoms, and 1 carbon number is
~5 alkyl group, halogen atom or cyano group,
R ₃ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, a nitro group, or a cyano group, R ₄ represents a divalent hydrocarbon group having 1 to 5 carbon atoms, and R ₅ represents a hydrogen atom or a methyl group. )