RU2466173C1 - Light-sensitive composition for light filters for protective and preventive purposes - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: light-sensitive composition contains 2,2-n-dianisyl-5,6-benzo-[2H]-chromene and 1,3,3-trimethyl-6'-formyl-8'-allyl-spiro-indoline-2,2'-[2H]-chromene in molar ratio 1:0.8-1.6, respectively. Photochromic polymer materials obtained from said composition have optimum optical properties needed to satisfy physiologically based requirements for protective and preventive optical materials: when illuminated with daylight, they "cut" off the spectral region from 400 to 555 nm, while keeping intensity of light incident on eyes with wavelength greater than 555 nm at a level of less than 30%, and in conditions of low-intensity dusk illumination provide full transmission of light with wavelength greater than 400 nm.

EFFECT: protecting eyes and preventing ophthalmic diseases associated with the damaging effect of optical radiation in the visible spectrum.

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Description

The invention relates to the field of ophthalmic optics, specifically to a photosensitive composition intended for the creation of protective filters for preventive purposes - photochromic polymer coatings for spectacle UV-absorbing lenses, with the aim of protecting the eyes and preventing ophthalmic diseases associated with the damaging effect of light radiation in the visible spectrum.

In the future, the terms “photosensitive” and “photochromic” will be used as synonyms.

It is known that the short-wave violet-blue region of visible light (400-500 nm) poses a potential danger to eye structures. Analysis of a large amount of known data on the effect of light on pathological processes in the organ of vision shows that irradiation with blue-violet light promotes the formation of reactive oxygen species, the accumulation of the final product of photolysis of the visual pigment rhodopsin — toxic, including phototoxic, fully trans-retinal and toxic products of its transformation, apoptosis of retinal pigment epithelial cells [M.A. Ostrovsky. Molecular mechanisms of the damaging effect of light on eye structures and systems of protection against such damage. // Successes in biological chemistry. 2005.V. 45. S.173-204]. A special risk group consists of people who have undergone surgical removal of the cataract lens, as a result of which the aphakic eye remains without natural light-filtering protection of the undesirable wavelength range, or people who have been implanted with a colorless (unpainted yellow) intraocular lens instead of a removed cataract lens. Both in the case of the aphakic eye, and in the case of implantation of a colorless intraocular lens, complications associated with photodamage of the retina and retinal pigment epithelium are very likely.

The strategy for the protection of the retina and retinal pigment epithelium and the prevention of pathologies associated with their photodamage is based on spectral correction methods involving the use of filters that "cut off" potentially dangerous parts of the spectral range of the light entering the eye (see monograph: Zak P., Egorova T. , Rosenblum Yu., Ostrovsky M. Spectral correction of vision: scientific foundations and practical applications // Scientific World, Moscow. 2005. P.454). As such filters, UV-absorbing lenses having photochromic properties, reversibly changing their optical characteristics under the influence of light radiation in the visible region of the spectrum, and returning to their original state after the termination of the light flux can be used.

The optical properties of photochromic lenses depend on the quantitative and qualitative composition of the photochromic compounds included in them. The necessary spectral light filtering characteristics can be realized by adding photochromic components to a colorless polymer melt in the manufacture of lenses or by applying polymer coatings with photochromic properties to finished lenses.

As photochromic components currently used, as a rule, compounds belonging to the groups of chromenes, spiropyrans (naphthopyranes), oxazines and several others.

Methods have been developed for the production of naphthopyran and phenanthropyran photochromic compounds, similar in structure to the photochromic part of the chromene proposed in the present invention and containing an additional annelated benzene ring in position 5, 6 [EP 1153021 A1, publ. November 14, 2001]. The prospects of using mixtures of various photochromes in the production of photochromic materials for ophthalmic purposes is shown, however, the requirements for the resulting photochromic materials (transmission region, percentage of filtered radiation depending on wavelength, etc.) are not formulated in the work. As a result, it is not clear from the description of the invention how well-proposed photochromic mixtures are suitable for creating effective ophthalmic products.

American patent [US 6367930, publ. April 9, 2002] describes the process of obtaining photochromic optical lenses by creating a photochromic layer using "lamination". Photochromic properties are provided by the use of compounds of the pyranes, oxazines, fulgides and fulgimides groups. A large, albeit non-systematic, list of naphthochromenes, spirooxazines and spiropyrans suitable for creating a photochromic layer in this process is proposed. Compounds were selected for high quantum yields, staining intensity, but excluding absorption zones in the UV range.

The invention is protected by US patent [US 7584630, publ. 09/08/2009], can serve as an example of a systematic approach to the development of photochromic materials for contact and intraocular lenses. Much attention was paid to achieving high absorption efficiency in the range of 280-380 nm (in accordance with the recommendations of the American National Institute of Standards), as well as the possibility of effective incorporation of the photochromic component into the hydrophilic in nature hydrogel used in soft contact lenses. As a photochromic component, it is proposed to use 2H-chromene type systems. However, the approach to the design of materials seems to be limited, since it does not take into account physiologically justified filtering regions in the short-wavelength range (400-520 nm).

Amino-based ophthalmic products having a photochromic coating are known [WO 0036049, publ. 06/22/2000]. The desired photochromic properties - fast and intense dimming during light activation and subsequent bleaching under the influence of ultraviolet radiation, are provided by the use of photochromic compounds, of which at least one has a maximum absorption in the range of 400-525 nm, and at least one has a maximum absorption in the region of 525-700 nm.

Known photochromic compositions intended for the production of sunscreens and ophthalmic products [RU 9912507 A, publ. 10.10.2001] and [RU 2177958 C2, publ. January 10, 2002], including as a photochromic compound, preferably, a combination of two dyes of the chrome type, which makes it possible to obtain a particularly applicable gray color of light filters. The composition includes 2- (n-dimethylaminophenyl) -2- (n-methoxyphenyl) -5-methyl-7,9-dimethoxy- [2H] -naphtho- [1,2b] pyran and 3- (n-methoxyphenyl) - 3-phenyl-6-morpholine- [3H] -naphtho- [2,1b] pyran in a mass ratio of components from 7 to 10, preferably from 8 to 9. Detailed attention in the description of the invention is given to methods for producing and studying the mechanical properties of compositions, and the photochromic properties of the obtained materials were evaluated one-sidedly (by measuring several parameters, for example, stainability and half-life), without paying due attention to the analysis of filtering characteristics, which is an obvious drawback of the study and does not allow us to assess the prospects of using the obtained samples for medical, ophthalmic purposes.

A common drawback of the described approaches is that the photochromic characteristics of the proposed filters, providing visual light comfort and satisfying the aesthetic needs of the consumer, do not fully take into account the physiological requirements for protecting healthy people and people with eye pathologies from the effects of light on the organs of vision. As a result, the range of “cut-off” wavelengths using known filters is not physiologically optimal.

Physiologically substantiated requirements for protective and preventive ophthalmic filters should be based on the laws of change in the spectral sensitivity of the eyes of healthy people depending on the nature of illumination, as well as on the results of studies of phototoxic processes occurring in the structures of the human eye under the influence of light of different spectral ranges. Figure 1 shows the so-called. "Visibility curves" of the human eye, reflecting the spectral sensitivity of the eye to radiation of various wavelengths under twilight (scotopic) and daylight (photopic) lighting.

The maximum sensitivity of the eye in daylight - the so-called. “Cone-shaped” vision (curve 2) is achieved at a wavelength of 555 nm, and in twilight light, when “rod-shaped” vision (curve 1) is mainly realized at a wavelength of 510 nm. Under intense daylight, the reticulum photoreceptor cells, the rods that provide twilight black-and-white vision, “do not work,” however, under the influence of light in the short-wavelength range, the visual pigment fades, resulting in the accumulation of fully trans-retinal and toxic products its transformation, which can lead to aggravation of the development of eye diseases.

Table 1 shows the results of experimental psychophysiological studies of patients with various pathologies of vision [Zak P., Egorova T., Rosenblum Yu., Ostrovsky M. Spectral correction of vision: scientific foundations and practical applications. // Scientific world, Moscow. 2005. P.454], which show that for different groups, depending on the symptoms of the disease, there are their own optimal limits of short-wave filtration, which allow to maximize the resolution of the eye.

Table 1 The optimal interval of short-wave light filtration for different types of ocular pathology Type of ocular pathology The boundaries of short-wave light filtration, nm glaucoma, cataract, aphakia, corneal dystrophy 450-475 central chorio-retinal dystrophy, diabetic retinopathy, partial optic atrophy, Still's disease, myopia 475-500 tapetoretinal abiotrophy (degenerative diseases of the retina), cone dysfunction, albinism, premature retinopathy, congenital maldevelopment of the macula, Marfan syndrome 500-520

The strategy for protecting the retina and retinal pigment epithelium involves a significant reduction in the amount of short-wave light reaching them. Protective and preventive filters in the conditions of daily intense light flux should cut off the short-wavelength part of the spectrum (λ = 400-500 nm) to the maximum extent, while passing a sufficient amount of light for normal visual perception - not less than the amount of light flux absorption of 0.3, in the region cone visibility curve (longer than 555 nm).

Under conditions of weak, twilight lighting, these filters should pass all available visible light to the retina, providing a satisfactory quality of twilight (scotopic) rod vision. Based on this, the upper limit of preventive light filtration for healthy people should be in the region of at least 555 nm, corresponding to the main band of spectral sensitivity of daytime (photopic) cone vision.

Thus, the use of light filters that attenuate the intensity of the light flux in the spectral region from 400 to 555 nm meets the physiological requirements for protecting the eyes of healthy people, as well as patients suffering from ophthalmic diseases. The shift of the filtration boundary towards longer wavelengths — beyond 555 nm — leads to a certain decrease in the visual acuity, however, such a decrease is justified, because allows you to more reliably protect the structure of the eye from damaging light exposure, improve the quality of twilight vision and reduce the risk of various pathologies.

Since the speed of dark and light adaptation of the visual system under normal physiological lighting conditions is in the minute range, the minute speed of dimming and enlightenment of the filter and, accordingly, the proposed composition must satisfy these physiological requirements

The objective of the present invention is to provide a photosensitive composition, which, when included in polymeric materials intended for the prophylactic protection of the eyes from damaging light exposure, gives these materials the following optical properties: when illuminated with daylight, the filters must "cut off" the spectral region in the range from 400 to 555 nm, while ensuring the intensity of light entering the eye with a wavelength above 555 nm at a level of at least 30%, and in low-light conditions with low intensity and these materials should provide full transmittance of light with a wavelength longer than 400 nm.

The problem is solved by the photochromic composition, including 2,2-n-dianisyl-5,6-benzo [2H] -chrome (compound 1) and 1,3,3-trimethyl-6'-formyl-8'-allyl-spiro -indolin-2,2 '- [2H] -chromene (compound 2) with the following molar ratios of components:

2,2-n-dianisyl-5,6-benzo [2H] -chrome - 1

1,3,3-trimethyl-6'-formyl-8'-allyl-spiro-indoline-2,2 '- [2H] -chrome - (0.8-1.6).

The chemical structure included in the proposed composition of compounds 1 and 2 is shown in Fig.2. Compound 1 is photochromic [2H] -chrome with n-anisyl substituents at position 2 of the pyran ring. Compound 2 contains a formyl and potentially polymerizable allyl group in the [2H] -chromene fragment, which allows it to be used, inter alia, as a photochromic copolymer at the polymerization stage in the preparation of the photochromic polymer coating.

2,2-n-dianisyl-5,6-benzo [2H] -chromene (compound 1) is prepared by reacting 5,6-benzocoumarin with n-methoxyphenyl magnesium bromide. The 5,6-benzocoumarin needed to prepare compound 1 was prepared by reacting 2-hydroxy-naphthaldehyde-1 with anhydrous sodium acetate in excess of acetic anhydride at a temperature of 180 ° in an autoclave [G. Kauffmann Chem. Ber. 1883, vol.16, p.683-686]. The procedure for obtaining compound 1 used by the authors is described below.

1,3,3-trimethyl-6'-formyl-8'-allyl-spiro-indoline-2,2 '- [2H] -chromene (compound 2) is prepared by reacting 1,2,3,3-tetramethylindolenyl perchlorate with 2 -hydroxy-3-allyl-5-formylbenzaldehyde in isopropyl alcohol with the addition of an equimolar amount of piperidine [B. Lukyanov, G. Vasilyuk, E. Mukhanov, LAgeev, M. Lukyanova, Y. Alexeenko, S. Besugliy, V. Tkachev “Multifunctional spirocyclic systems "International Journal of Photoenergy, vol. 2009 (2009), Article ID 689450, 6 pages]. 1,2,3,3-tetramethylindolenyl perchlorate is obtained by the reaction of a commercial 1,3,3-trimethyl-2-methyleneindoline (Fischer base ) with perchloric acid according to the method of [Reichardt, C .; Budnik, U. Ch emische Berichte, 1990, vol. 123, No. 10, p.2023-2030]. 2-hydroxy-3-allyl-5-formylbenzaldehyde is obtained by the excessive formylation of 1-hydroxy-2-allylbenzene [B.S. Lukyanov, N. A. Voloshin // Method for the preparation of 5-substituted 4-hydroxy-isophthalic aldehydes // AS No. 1830902 (USSR), 1992. The procedure for the preparation of compound 2 used by the authors is described below.

The photochromic properties of compounds 1 and 2 included in the proposed composition and various variants of the proposed photosensitive composition in solution or in the composition of polymer films are characterized by electronic absorption spectra (Agilent 5483 spectrophotometer, United States) obtained before and after irradiation of samples with an excitation light source, which is used as a mercury DRSh-250 lamp with light filters emitting light with λ _max = 400 and 578 nm. To determine the range of concentrations of the components of the photochromic composition, the absorption spectra are recorded in solutions in toluene (concentration C = 7.4 × 10 ^-5 ) imitating a polystyrene matrix, which is mainly used for light-protective photochromic glasses.

The photochromic properties of compound 1 are characterized by the electronic absorption spectra shown in FIG. 3. When the solution of compound 1 is irradiated in a stationary mode at room temperature with a wavelength of 400 nm, the solution becomes colored and absorption bands of a colored photoinduced merocyanine form (λ _max = 477 nm) appear, having a bathochromic shift as compared with the absorption spectrum of the original 2,2-n- dianisyl-5,6-benzo [2H] -chromene (see Fig. 3a). After the cessation of irradiation, discoloration of the solution is observed (see Fig. 3b). The photochromic properties of compound 2 are characterized by the electronic absorption spectra shown in FIG. 4. When the solution of compound 2 is irradiated in a stationary mode at room temperature with a light wavelength of 400 nm, the solution is colored, and the absorption bands of the colored photoinduced merocyanine form λ _max = (500-700) nm are observed (see Fig. 4a). After the cessation of irradiation, discoloration of the solution is observed (see Fig. 4b).

In order to search for the optimal quantitative ratios of compounds 1 and 2, providing photosensitive compositions that meet the physiologically substantiated requirements for protective filters, the spectral characteristics of compositions comprising compounds 1 and 2 in the range of molar ratios from 1: 0.25 were determined to 1: 4. To prepare samples of compositions, we used equimolar solutions of compounds 1 and 2 in toluene with an initial concentration of C = 7.4 × 10 ^-5 M each. Based on the analysis of the absorption spectra of the obtained photosensitive compositions, the range of molar ratios of compounds 1 and 2 was selected in which the spectral properties of the composition satisfy physiologically justified requirements, namely: the molar ratio between compounds 1 and 2 should be in the range from 1: 0.8 to 1: 1.6. Outside of this interval, i.e. in cases where the number of moles of the 1,3,3-trimethyl-8'-formyl-spiro-indolin-2,2 '- [2H] -chromene (compound 2) in the composition per mole of 2.2- n-dianisyl-5,6-benzo [2H] -chromene (compound 1) is less than 0.8 or more than 1.6, the photosensitive composition no longer meets the requirements for it: with a lack of compound 2 (the molar fraction of compound 2 is less 0.8) there is insufficient filtration of the short-wavelength light range, and damaging short-wave radiation is incident on the retina of the gas and epithelium, and When its excess (mole fraction of Compound 2 is greater than 1.6) there is significant absorption in the long wavelength light range that does not provide a satisfactory quality of rod-shaped.

Description of drawings

Figure 1 shows the "visibility curves" of human vision: 1 - spectral sensitivity of twilight (rod) vision, 2 - spectral sensitivity of daytime (cone) vision.

Figure 2 shows the chemical structure of compounds 1 and 2 included in the proposed composition.

Figure 3 shows the change in the absorption spectrum of a solution of compound 1 in toluene (C = 7.4 × 10 ^-5 M): a - during irradiation with light λ = 400 nm (dt = 1 sec), b - reverse dark reaction - after termination of exposure (dt = 1 sec).

Figure 4 shows the change in the absorption spectrum of a solution of compound 2 in toluene (C = 7.4 × 10 ^-5 M): a - in the process of irradiation with light λ = 400 nm (dt = 1 sec), b - reverse dark reaction after termination irradiation (dt = 1 sec).

Figure 5 shows the absorption spectra of samples of the photochromic polymer coating obtained in examples 1-3, before irradiation (curve 1) and after irradiation (curve 2): a - sample obtained in example 1, b - sample obtained in example 2 , in - the sample obtained in example 3.

Obtaining 2,2-n-dianisyl-5,6-benzo [2H] -chromene (compound 1)

In a three-necked flask with a capacity of 0.5 l, 100 ml of absolute ether, 2.4 g (0.1 g-at) of magnesium metal are placed. 12.5 ml (18.7 g - 0.1 M) of n-bromoanisole dissolved in 50 ml of absolute ether are added dropwise through a separatory funnel at such a rate that the reaction mixture boils slightly without an external supply of heat. After the total amount of magnesium has been dissolved, a solution of 10.6 g (0.05 M) of 5,6-benzocoumarin in 100 ml of absolute ether is carefully pinned to the resulting solution of n-methoxy-phenyl magnesium bromide. The reaction mixture was carefully decomposed with a saturated solution of ammonium chloride, the ether layer was separated, the aqueous layer was extracted with 3-50 ml of ether, the combined extracts were dried with anhydrous sodium sulfate, the ether was distilled off, and the obtained product was purified by chromatography on a column filled with aluminum oxide (eluent was chloroform). Yield ~ 1 g.

2,2-n-Dianisyl-5,6-benzo [2H] -chrome is a colorless crystal with a melting point of 162 ° C, soluble in toluene.

The structure of the obtained 2,2-n-dianisyl-5,6-benzo [2H] -chromene was confirmed by elemental analysis, as well as IR and ¹ H NMR spectroscopy.

Obtaining 1,3,3-trimethyl-6'-formyl-8'-allyl-spiro-indoline-2,2 '- [2H] -chromene (compound 2)

To a solution of 190 mg (0.001M) of 2-hydroxy-3-allyl-5-formylbenzaldehyde and 274 mg (0.001M) of 1,2,3,3-tetramethylindolenyl perchlorate in 5 ml of propanol-2 was added dropwise with heating 0.1 ml (0.0011 M) piperidine. The reaction mixture is boiled for 10 minutes and cooled. The precipitate was filtered off and recrystallized. The product was isolated from the reaction mixture as bright red crystals, which were then recrystallized from hexane. After recrystallization, light brick crystals with a melting point of 84 ° C., soluble in toluene, are obtained. Yield 193 mg.

The structure of the obtained 1,3,3-trimethyl-6'-formyl-8'-allyl-spiro-indolin-2,2 '- [2Н] -chrome was confirmed by elemental analysis, as well as by IR and ¹ H NMR spectroscopy .

The following examples show possible, but not exhaustive applications of the inventive photosensitive compositions to create protective polymer photochromic coatings. Polystyrene was used as a polymer matrix in the examples, however, this does not exclude the possibility of incorporating the claimed compositions into other polymers suitable for ophthalmic optics that are soluble in the same solvents as compounds 1 and 2, for example polymethylmethacrylate, oligocarbonate methacrylate, copolymers of 2-hydroxyethyl methacrylate and dimethacrylate with ethylene glycol, polymers based on polyvinyl alcohol.

Example 1. Obtaining and photochromic properties of a polymer film of polystyrene containing 2,2-n-dianisyl-5,6-benzo [2H] -chromene (compound 1) and 1,3,3-trimethyl-6'-formyl- 8'-allyl-spiro-indoline-2,2 '- [2H] -chromene (compound 2) in a molar ratio of 1: 1.6.

A sample of 1.5 g of optical polystyrene of thermal polymerization is dissolved by heating in 2 ml of spectral purity toluene. To prepare a solution of the photochromic composition, 20 mg (5.08 × 10 ^-5 mol) of compound 1 was dissolved in 1.5 ml of spectral purity, 28 mg (8.11 × 10 ^-5 mol) of compound 2 was dissolved in 1.5 ml of toluene spectral purity, the resulting solutions are mixed in a volume ratio of 1: 1, after which 3 ml of the resulting solution containing compounds 1 and 2 in a molar ratio of 1: 1.6 is introduced into the polystyrene solution with stirring. The resulting mixture was stirred for 1 hour using a magnetic stirrer. When the solvent is evaporated from the resulting mixture in the mold at room temperature, a transparent polystyrene film 0.05 mm thick containing the photochromic composition is obtained.

Figure 5a shows the electronic absorption spectra of the obtained film before and after irradiation in a stationary mode. A DRSh-250 mercury lamp equipped with a 365 nm filter that cuts out light with λ _max <400 nm is used as a source of activating radiation. As can be seen from the figure, prior to irradiation (curve 1), the film sample is almost transparent to visible light. When a mercury lamp (λ <400 nm), which simulates bright daylight, is irradiated for 5 sec, simulating bright daylight, the sample acquires a darker color, and an absorption band appears in the spectrum with a maximum at λ = 480 nm with a shoulder of 615 nm, while the overlap region , limited by the optical density D = 0.3, extends up to ~ 640 nm (curve 2).

After the cessation of illumination, simulating the conditions in which twilight (wand) vision is carried out, for no more than 10 minutes the polymer film becomes almost colorless and transparent to all the light entering it.

Thus, the combination of optical properties of the obtained photochromic film satisfies the physiologically substantiated requirements for protective and preventive optical materials formulated above.

Example 2. Obtaining and photochromic properties of a polymer film of polystyrene containing 2,2-n-dianisyl-5,6-benzo [2H] -chromene (compound 1) and 1,3,3-trimethyl-6'-formyl- 8'-allyl-spiro-indoline-2,2 '- [2H] -chromene (compound 2) in a molar ratio of 1: 0.8.

A portion of 2.5 g of optical polystyrene of thermal polymerization is dissolved by heating in 3 ml of spectral purity toluene. To prepare a solution of the photochromic composition, 42 mg (1.07 × 10 ^-4 mol) of compound 1 was dissolved in 2.5 ml of spectral grade toluene, 30 mg (8.696 × 10 ^-5 mol) of compound 2 was dissolved in 2.5 ml of spectral grade toluene , the resulting solutions are mixed in a volume ratio of 1: 1, after which 5 ml of the resulting solution containing compounds 1 and 2 in a molar ratio of 1: 0.8 is introduced into the polystyrene solution with stirring. The resulting mixture was stirred for 1 hour using a magnetic stirrer. When the solvent is evaporated from the resulting mixture in the mold at room temperature, a transparent polystyrene film 0.08 mm thick containing the photochromic composition is obtained.

Figure 5b shows the electronic absorption spectra of the obtained film before and after irradiation in a stationary mode under conditions similar to Example 1. As can be seen from the figure, before irradiation, the film sample is practically transparent to visible light (curve 1). When irradiated for 5 seconds, simulating bright daylight, the sample becomes colored, an absorption band appears in the spectrum with a maximum at λ = 481 nm, while the overlap region limited by the optical density D = 0.3 extends to ~ 570 nm (curve 2). After the cessation of lighting, simulating the conditions in which twilight (wand) vision is carried out, within 10 minutes the polymer film becomes almost colorless and transparent to all the light entering it.

Thus, the combination of optical properties of the obtained photochromic film satisfies the physiologically substantiated requirements for protective and preventive optical materials formulated above.

Example 3. Obtaining and photochromic properties of a polymer film of polystyrene containing 2,2-n-dianisyl-5,6-benzo [2H] -chrome (compound 1) and 1,3,3-trimethyl-6'-formyl- 8'-allyl-spiro-indolin-2,2 '- [2H] -chromene (compound 2) in a molar ratio of 1: 1.33.

A portion of 1.9 g of optical polystyrene of thermal polymerization is dissolved by heating in 3 ml of spectral purity toluene. To prepare a solution of the photochromic composition, 6 mg (1.52 × 10 ^-5 mol) of compound 1 was dissolved in 2.2 ml of spectral purity, 7 mg (2.029 × 10 ^-5 mol) of compound 2 was dissolved in 2.2 ml of spectral purity , the resulting solutions are mixed in a volume ratio of 1: 1, after which 4.4 ml of the resulting solution containing compounds 1 and 2 in a molar ratio of 1: 1.33 is introduced into the polystyrene solution. The resulting mixture was stirred for 1 hour using a magnetic stirrer. When the solvent is evaporated from the obtained mixture in the mold at room temperature, a transparent polystyrene film 0.06 mm thick containing the photochromic composition is obtained.

Figure 5c shows the electronic absorption spectra of the obtained film before and after irradiation in a stationary mode under conditions similar to Example 1. As can be seen from the figure, before irradiation, the film sample is practically transparent to visible light (curve 1). When irradiated for 5 seconds, simulating bright daylight, the sample becomes colored, and an absorption band appears in the spectrum with a maximum at λ = 480 nm with a shoulder of 615 nm, while the overlap region limited by the optical density D = 0.3 extends to ~ 580 nm (curve 2). After the cessation of lighting, simulating the conditions in which twilight (wand) vision is carried out, within 10 minutes the polymer film becomes almost colorless and transparent to all the light entering it.

Thus, the combination of optical properties of the obtained photochromic film satisfies the physiologically substantiated requirements for protective and preventive optical materials formulated above.

Claims (1)

A photosensitive composition for protective filters, including 2,2-n-dianisyl-5,6-benzo [2H] -chrome and 1,3,3-trimethyl-6′-formyl-8′-allyl-spiro indolin-2,2 ′ - [2H] -chrome at the following molar ratios of components:
2,2-n-dianisyl-5,6-benzo [2H] -chrome one 1,3,3-trimethyl-6′-formyl-8′-allyl-spiro indolin-2,2 ′ - [2H] -chrome 0.8-1.6

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