JP2017058611A - Optical product including photochromic layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical product that has an excellent photochromic characteristic, that is, high coloring concentration, and fast decoloring velocity.SOLUTION: An optical product is provided that includes a plurality of photochromic layers each containing a photochromic compound. When the photochromic layer present at a position most distant from a side where light enters is defined as a first photochromic layer, a decoloring half-life of the first photochromic layer is slower than that of the other photochromic layers.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a novel optical article having a plurality of photochromic layers. More specifically, the present invention relates to a novel optical article having a photochromic layer, which has a high color density and excellent color fading characteristics.

  Photochromism is a reversible action that quickly changes color when a compound is irradiated with light containing ultraviolet light, such as sunlight or light from a mercury lamp, and returns to its original color when light is turned off and placed in a dark place. It is applied to various uses. As photochromic compounds having such properties, fulgimide compounds, spirooxazine compounds, chromene compounds and the like have been found. Since these compounds can be made into optical articles having photochromic properties by being compounded with plastics, many studies have been made on compounding.

  For example, photochromism is also applied in the field of spectacle lenses. Photochromic eyeglass lenses that use photochromic compounds function as sunglasses by rapidly coloring the lens outdoors when exposed to light containing ultraviolet rays such as sunlight, and fading indoors where there is no such light irradiation. It functions as normal transparent glasses, and its demand has increased in recent years.

  As photochromic eyeglass lenses, those obtained by imparting photochromic performance to a plastic lens are widely used from the viewpoint of lightness and safety. In order to impart photochromic performance to a plastic lens, generally, an organic photochromic compound is used, and photochromic properties are imparted to the plastic lens by various methods. For example, photochromic eyeglass lenses are manufactured by a method called a coating method. Specifically, a photochromic curable composition containing a radical polymerizable component and a photochromic compound is applied to the surface of a plastic lens substrate and cured to produce a photochromic lens (photochromic laminate) having a photochromic layer. Is the method. This coating method is an excellent method in that photochromic performance can be imparted regardless of the material of the plastic lens.

  In photochromic eyeglass lenses, it is necessary to block out sunlight enough as sunglasses outdoors and to fade quickly when returning indoors to ensure good visibility. Is particularly sought after. However, in principle, the color density and the fading speed of the photochromic compound are in a trade-off relationship, and a photochromic dye having a high color density tends to have a slow fading speed.

  In order to improve the color density, there are methods to increase the amount of photochromic compound (pigment) in the photochromic layer or to increase the film thickness of the photochromic layer. The improvement effect will reach saturation. This is because all sunlight (ultraviolet light) necessary for the ring-opening reaction of the photochromic compound (dye) is absorbed. In addition, photochromic compounds (pigments) are often slightly colored even in the absence of light. If the blending amount or film thickness is too high, the transparency of the lens when no color is developed decreases. There was also a problem to do.

  For this reason, in an actual photochromic eyeglass lens, the type and amount of the photochromic compound are determined in consideration of a practical balance between the color density and the fading speed. That is, select and use a photochromic compound with a good balance between color density and fading speed, or mix dyes with high color density (low fading speed) and dyes with low color density (fast fading speed). I am using it.

  On the other hand, by optimizing the radical polymerizable component (radical polymerizable composition) that becomes the matrix of the photochromic layer, it is also possible to develop color by designing the photochromic compound so that it does not hinder structural changes associated with ring-opening and ring-closing reactions. It is possible to improve the density and fading half-life (fading speed).

  For example, a method is known in which the ratio of an acrylic monomer and a methacrylic monomer in a photochromic curable composition is limited to improve photochromic properties and adhesion of a hard coat layer (Patent Document 1). Moreover, the method of improving the photochromic characteristic and surface hardness of the photochromic layer obtained by mix | blending a silsesquioxane monomer with a photochromic curable composition is also examined (patent document 2).

  However, according to the study by the present inventors, the method described in Patent Document 1 tends to decrease the surface hardness of the resulting photochromic layer when attempting to improve the photochromic characteristics. On the contrary, when the surface hardness was improved, the photochromic characteristics tended to decrease. In the method described in Patent Document 2, the surface hardness of the photochromic layer can be improved by using a silsesquioxane monomer. However, although the resulting photochromic layer is considered to be caused by a decrease in flexibility, appearance defects such as cracks may occur after the formation of the photochromic layer or in a hard coating process that is a subsequent process. It was.

  As described above, there is room for improvement in order to improve the photochromic properties by the radically polymerizable composition of the prior art and to satisfy the other properties to a high degree.

  On the other hand, an optical substrate using a plurality of photochromic layers has also been reported. For example, it is disclosed that the temperature dependency of the color density is improved by laminating another photochromic material having a low temperature dependency of absorbance on the photochromic material (see Patent Document 3). It has also been reported that the color density and its temperature dependency are improved by laminating a plurality of layers of photochromic materials having different absorption bands and temperature characteristics (see Patent Document 4).

  However, none of Patent Documents 3 and 4 discloses a method for obtaining an excellent fading rate (half-life) although the color density and its temperature dependency can be improved. For example, in Patent Document 3, there is an example of laminating a photochromic layer on a photochromic lens, but a photochromic compound included in the photochromic lens is not disclosed, and a photochromic material having a low temperature dependency is simply laminated. It only shows.

International Publication No. 2011-125156 Pamphlet International Publication No. 2013/008825 Pamphlet U.S. Pat. No. 7,320,826 US Publication No. 2014/0334026

  Accordingly, an object of the present invention is to provide an optical article having excellent photochromic properties, that is, a high color density and a fast fading speed.

  The inventors of the present invention have made extensive studies in order to solve the above problems. As a result, the photochromic layer is multi-layered, and the photochromic layer with a fast fading half-life is provided on the upper side (light incident side) of the photochromic layer with a slow fading half-life, resulting in a higher color density and faster fading half-life. I found. Furthermore, the absorption edge of the absorption spectrum of the upper photochromic layer with a fast fading half-life when not colored is shorter than the absorption edge of the absorption spectrum of the lower photochromic layer with a slower fading half-life when not developing. Thus, the color density was further improved, and the present invention was completed.

  That is, the present invention is an optical article having a plurality of photochromic layers containing a photochromic compound, and when the photochromic layer located farthest from the light incident side is the first photochromic layer, the fading of the first photochromic layer An optical article characterized by having a half-life that is slower than the fading half-life of other photochromic layers.

  In the present invention, the fading half-life is described in detail in the following examples. When the photochromic layer is irradiated with light for 300 seconds and then the light irradiation is stopped, a difference spectrum (absorption spectrum at the time of color development) It refers to the time (seconds; sec.) Required for the absorbance at the maximum absorption wavelength in the absorption spectrum when no color develops to decrease to ½ (half). When two or more absorption peaks exist in the photochromic layer, the fading half-life refers to the time until the value of the absorption peak having the highest absorbance (absorbance at the maximum absorption wavelength) becomes half.

  In the present invention, in order to further increase the color density, it is preferable that the absorption edge of the first photochromic layer has a shorter wavelength than the absorption edges of the other photochromic layers.

  In the present invention, the absorption edge refers to a wavelength at which the transmittance spectrum of the photochromic layer before light irradiation is measured and the transmittance is 50% is defined as the absorption edge.

  ADVANTAGE OF THE INVENTION According to this invention, the optical article which has the outstanding photochromic characteristic, ie, a high coloring density, and the outstanding color release characteristic can be provided.

FIG. 1 schematically shows a process in which excitation light incident on an optical article is absorbed and attenuated in a photochromic layer. It is the schematic which shows an example of the optical article of this invention. FIG. 3 is a diagram schematically showing the relationship between excitation light irradiation intensity and color density in a photochromic layer having a fast fading half-life and a photochromic layer having a slow fading half-life. FIG. 4 is a graph plotting the color density against the fading half-life. FIG. 5 is a graph plotting the color density against the fading half-life. FIG. 6 is a transmittance spectrum of the photochromic layer before light irradiation.

  The optical article of the present invention is an optical article in which a plurality of photochromic layers containing a photochromic compound are laminated on an optical substrate, and the photochromic layer located farthest from the light incident side is defined as the first photochromic layer. In some cases, the fading half-life of the first photochromic layer is slower than the fading half-life of other photochromic layers.

  In the present invention, the light incident side is, for example, as shown in FIG. For example, when the optical article of the present invention is used as a spectacle lens, when the spectacles having the lens are worn, if light is incident from the upper side to the lower side (direction 10 of light incidence), The one closest to the eye becomes the first photochromic layer. FIG. 2 shows an example of the optical article of the present invention. The optical article includes an optical substrate 6, a first photochromic layer 7, and another photochromic layer 8 (when the other layer is one layer). It is an example). In the present invention, if the color fading half-life is faster than that of the first photochromic layer, the optical substrate 6 can be regarded as one type of photochromic layer by containing a photochromic compound. Hereinafter, the direction in which another photochromic layer is located from the first photochromic layer may be referred to as the upper side.

  In the present invention, the fade half-life of the photochromic layer is difficult to confirm the fade half-life of each layer alone after the optical article is manufactured. Therefore, in the present invention, a single-layer photochromic layer may be formed in advance, and an optical article that satisfies the requirements of the present invention may be formed from the value of the fading half-life. In addition, since the color density and the absorption edge vary depending on the thickness of the photochromic layer, the photochromic curable composition and the curing conditions are the same, and single photochromic layers having different thicknesses are manufactured in advance and configured. The color density and absorption edge should be examined. As described above, if the photochromic curable composition, the curing conditions, and the thickness of the photochromic layer are the same, the photochromic characteristics of the photochromic layer obtained by once curing are hardly changed. Therefore, in the present invention, a single-layer photochromic layer is formed in advance, the photochromic characteristics of the layer are confirmed, and the optical article of the present invention is manufactured.

  In addition, a single-layer photochromic layer is formed by forming a single-layer photochromic layer on an optical substrate with known optical properties, and subtracting the properties of the optical substrate to obtain a fading half-life, color density, and absorption edge. Can be sought. Alternatively, a single photochromic layer may be formed and the characteristics of the single layer may be examined. However, depending on the application, it may be necessary to reduce the thickness of the photochromic layer, so a single-layer photochromic layer is formed on an optical substrate with known optical properties, and its properties (fading half-life, color density) It is preferable to employ a method for obtaining the absorption edge.

(Photochromic layer)
The optical article of the present invention has a first photochromic layer having the slowest fading half-life and another photochromic layer having a faster fading half-life.

  To adjust the fading half-life of the photochromic layer to be different between the upper side (other photochromic layer) and the lower side (first photochromic layer), the type and blending ratio of the photochromic compound and / or radical polymerization that becomes the matrix What is necessary is just to change the kind and mixture ratio of a sex component. However, the method of changing the type and blending ratio of the photochromic compound can easily make a difference in the fading half-life. In a photochromic compound having a similar structure, a coloring color density tends to be higher as a dye (photochromic compound) having a slower fading half-life.

  In the present invention, by providing another photochromic layer having a faster fading half-life than the first photochromic layer above the first photochromic layer having a slow fading half-life (the side on which light is incident), The photochromic characteristics can be improved as compared with the case where one photochromic layer and the other photochromic layer have the same fading half-life, or when the positions of the first photochromic layer and the other photochromic layer are reversed. In particular, the color density can be increased and the fading half-life can be increased. This is presumably due to the following reasons.

  The photochromic compound reacts by absorbing mainly ultraviolet light (hereinafter also referred to as excitation light) contained in sunlight and the like, and forms a color former (or a ring-opened body in the case of a chromene compound) to develop color. This colored body returns to a colorless body (closed ring in the case of a chromene compound) by heat (or visible light). For this reason, while the excitation light is exposed, a colorless body and a color body coexist in the photochromic layer, and both absorb the excitation light.

  FIG. 3 is a diagram schematically showing the relationship between excitation light irradiation intensity and color density in a photochromic layer having a fast fading half-life and a photochromic layer having a slow fading rate. Color development density change 11 of a dye having a slow fading half-life (corresponding to color development density change of the first photochromic layer in the present invention) is a color development density change 12 of a dye having a fast fading half-life (in the present invention, Compared to the change in the color density of the photochromic layer), the color density increases rapidly with the intensity of the excitation light, and the color density tends not to change much from the intensity of the excitation light above a certain level. . This is because when the intensity of the excitation light exceeds a certain level, most of the photochromic compound (dye) in the photochromic layer becomes a ring-opened body, so that the color density reaches saturation. Of the excitation light absorbed by the photochromic compound in the photochromic layer, the excitation light absorbed by the color former does not contribute to the color development reaction and is consumed as heat by the intramolecular relaxation process. Therefore, when a photochromic compound having a slow fading half-life is used, if the intensity of incident excitation light is too high, the loss of excitation light due to absorption of the color former increases.

  FIG. 1 is an example in the case where excitation light is incident on the optical article having the configuration shown in FIG. 2, and schematically shows a process in which excitation light is absorbed by the photochromic layer when the excitation light is incident on the photochromic layer. It is a thing. As shown in FIG. 1, the light amount 1 of the excitation light that has entered the other photochromic layer 2 is absorbed by the photochromic compound, and thus attenuates exponentially in the other photochromic layer 2. Then, the excitation light attenuated by the other upper photochromic layer 2 enters the lower first photochromic layer 3. Depending on the absorbance of the excitation light in each layer, the amount of light 4 absorbed in the other upper photochromic layer 2 tends to be larger than the amount of light 5 absorbed in the lower first photochromic layer 3. is there. Since the photochromic layer has the characteristics as described above, a photochromic layer having a fast fading half-life (other photochromic layer) is arranged on the upper side where excitation light is incident, and a photochromic layer having a slow fading half-life (first photochromic layer) ) On the lower side, the loss of excitation light due to absorption of the color former can be reduced. As a result, it is considered that the color density can be improved because the use efficiency of excitation light as the whole optical article is improved. Further, in a general photochromic compound, the molar extinction coefficient is increased by changing from a colorless body to a chromophore, so that the loss of excitation light by the chromophore further increases, and thus the above-mentioned effect tends to appear more remarkably. There is. Furthermore, by arranging a photochromic layer (other photochromic layer) with a fast fading half-life on the upper side (incident side of excitation light) where excitation light intensity is high, the photochromic layer (other photochromic layer) with a fast fading half-life The contribution can be made larger. That is, it is considered that the photochromic compound in the photochromic layer (other photochromic layer) having a fast fading half-life can be made into a ring-opened body, so that the fading half-life of the entire optical article can be shortened.

First Photochromic Layer and Other Photochromic Layer In the present invention, the film thickness ratio between the first photochromic layer and the other photochromic layer is preferably adjusted as appropriate depending on the color density and the fading half-life of the target optical article. By increasing the ratio of the upper layer (a layer having a fast fading half-life; another photochromic layer) (thickening the film thickness), the fading half-life of the obtained optical article can be increased. Conversely, by increasing the ratio of the first photochromic layer (increasing the film thickness), the color density of the resulting optical article can be increased. A preferable range of the film thickness ratio is that when the thickness of the first photochromic layer is 1, the thickness of the other photochromic layer (upper layer) is from the viewpoint that the effect of improving the photochromic characteristics by stacking the photochromic layers is high. A range of 0.2 to 4 is preferable. When the optical article is used for a spectacle lens, the actual thickness of the first photochromic layer is preferably 5 to 100 μm.

  The difference in fading half-life between the first photochromic layer and other photochromic layers is not particularly limited if the fading half-life of the first photochromic layer is slow, but the effect obtained (fast fading half-life, high color density) ) In consideration of 20 to 150 sec. (Second) is preferable (the fading half-life of the first photochromic layer is 20 sec. To 150 sec. Slower than the fading half-life of the other photochromic layers). Difference in fading half-life is 20 to 150 sec. By being in this range, a more excellent effect is exhibited, and the effect of reducing the so-called tailing, in which the color does not return completely upon fading and the coloring continues for a long time, is exhibited. In order to exhibit this effect more, the difference in fading half-life is preferably 20 to 100 sec., And 20 to 80 sec. It is more preferable that it is 20 to 70 sec.

  In the present invention, it is more preferable that the absorption edge of the absorption spectrum when the other photochromic layer is not colored be shorter than the absorption edge of the absorption spectrum when the first photochromic layer is not colored. By doing so, the first photochromic layer can absorb light in the long wavelength region that was not absorbed by the upper layer (other photochromic layer), so that the excitation light can be used efficiently, and the overall color development. The concentration can be further improved. The difference between the absorption edge of the other photochromic layer and the absorption edge of the first photochromic layer (difference in wavelength length) is not particularly limited. Considering the point, it is preferably 0 to 50 nm, and more preferably 5 to 30 nm. Also, the value of the absorption edge of the first photochromic layer is not particularly limited, but is preferably 380 to 450 nm, and preferably 400 to 430 nm, from the viewpoint of transparency and color density when uncolored. Is more preferable.

  In the optical article, the first photochromic layer is naturally only one layer, but other photochromic layers can be present in two or more layers. When two or more other layers are present, the fading half-life of all other photochromic layers must be faster than the fading half-life of the first photochromic layer. And in order to exhibit the effect of this invention most, it is preferable to arrange | position another photochromic layer so that a color fading half-life may become quicker as the layer which exists on the upper side. When two or more other photochromic layers are present, the difference in fading half-life from the first photochromic layer is 20 to 150 sec. In the fading half-life of all other photochromic layers. It is preferable to satisfy this range. In this case, the thickness ratio may be a comparison between the thickness of the first photochromic layer and the total thickness of all other photochromic layers. When there are two or more other photochromic layers, it is preferable that the absorption edge of the first photochromic layer has a shorter wavelength than the absorption edges of all the other photochromic layers. It is preferable that the color density value of is higher than the maximum color density value of all other photochromic layers.

  In the present invention, the first photochromic layer and the other photochromic layer may be disposed on the same surface side of the optical base material when laminated as a coating layer on the optical base material (first photochromic layer / Other photochromic layers / optical substrates, or optical substrates / first photochromic layers / other photochromic layers may be arranged in this order), and other photochromic layers may be disposed on the main surface on which light is incident. The first photochromic layer may be disposed on the back side of the main surface (the first photochromic layer / optical substrate / other photochromic layer may be disposed in this order). Further, when two or more other photochromic layers are present, any stacked structure may be employed as long as the first photochromic layer is disposed at a position farthest from the light incident side.

  Further, there is no particular limitation between the optical substrate, the first photochromic layer, and the other photochromic layer, but other coat layers such as a primer coat layer for improving adhesion, scratch resistance, etc. It is also possible to provide a known layer such as a hard coat layer that can improve the properties. In addition, an optical base material can also be made into a photochromic layer.

  In the optical article of the present invention, various laminated structures as described above can be adopted. Above all, the first photochromic layer and other photochromic layers are arranged on the surface of the optical substrate on which light is incident from the viewpoint of easy manufacture of the optical article and the ability to manufacture optical articles of various materials. It is preferable. Furthermore, in consideration of productivity, the other photochromic layer is preferably only one layer, and is preferably directly laminated on the first photochromic layer.

  In the present invention, the absorption peak of each of the first photochromic layer and the other photochromic layer may be adjusted so that a desired color tone is obtained when light is irradiated (incident). Therefore, the first photochromic layer and other photochromic layers can contain one type or two or more types of photochromic compounds. And what is necessary is just to confirm a fading half-life, color development density, and an absorption edge as a layer containing these photochromic compounds. From the viewpoint of constituting the color tone, the difference between the maximum absorption wavelength of the first photochromic layer (the wavelength of the absorption peak at which the absorbance is maximized) and the maximum absorption wavelength of other photochromic layers is preferably 50 nm or less. , 30 nm or less is more preferable, 20 nm or less is further preferable, and 10 nm or less is particularly preferable. Most preferably, both have the same maximum absorption wavelength (the difference is 0).

  In this invention, a 1st photochromic layer and another photochromic layer can be manufactured by a well-known method. Usually, a photochromic layer is formed by preparing a photochromic curable composition containing a radical polymerizable component, a photochromic compound, and other components to be blended as necessary, and effecting the composition. Next, the photochromic curable composition will be described.

(Photochromic curable composition for forming a photochromic layer)
The present invention is an optical article having a plurality of photochromic layers on an optical substrate. As described above, the photochromic layer can be formed of a photochromic curable composition containing a radical polymerizable component, a photochromic compound, and other components blended as necessary. Moreover, it is good also as a photochromic composition by using a polymer instead of the said radically polymerizable component.

(Photochromic compound)
As the photochromic compound used in the present invention, a compound exhibiting a photochromic action can be employed. For example, photochromic compounds such as fulgide compounds, chromene compounds, and spirooxazine compounds are well known, and in the present invention, these photochromic compounds can be used without any limitation. These may be used alone or in combination of two or more in each photochromic layer. The photochromic compound suitable for each photochromic layer of the present invention can be selected and used in consideration of the color density, fading half-life, color tone, etc. of each photochromic compound.

  Examples of the fulgide compound, the chromene compound, and the spirooxazine compound are described in JP-A-2-28154, JP-A-62-228830, WO94 / 22850, WO96 / 14596, and the like. Compounds.

  Further, as compounds having excellent photochromic properties, for example, JP 2001-114775 A, JP 2001-031670 A, JP 2001-011067 A, JP 2001-011066 A, JP 2000-347346 A, JP 2000-2000 A. JP-A-344762, JP-A No. 2000-344761, JP-A No. 2000-327676, JP-A No. 2000-327675, JP-A No. 2000-256347, JP-A No. 2000-229976, JP-A No. 2000-229975, JP-A No. 2000- No. 229974, JP-A No. 2000-229773, JP-A No. 2000-229972, JP-A No. 2000-219687, JP-A No. 2000-219686, JP-A No. 2000-219865, JP-A No. 11-322739, JP-A No. 11-286484 No., JP-A-11- 79171, JP 10-298176, JP 09-218301, JP 09-124645, JP 08-295690, JP 08-176139, JP 08-157467, US Pat. No. 5,645,767. US Pat. No. 5,658,501, US Pat. No. 5,961,892, US Pat. No. 6,296,785, Japanese Patent No. 42494981, Japanese Patent No. 4424962, WO 2009/136668, WO 2008/023828, Japanese Patent Japanese Patent No. 4369754, Japanese Patent No. 4301621, Japanese Patent No. 4256985, Pamphlet of WO2007 / 086532, JP2009-120536A, JP2009-67754A, JP2 09-67680, JP-A-2009-57300, Japanese Patent No. 4195615, Japanese Patent No. 41588881, Japanese Patent No. 4157245, Japanese Patent No. 4157239, Japanese Patent No. 4157227, Japanese Patent Japanese Patent No. 4118458, Japanese Patent Application Laid-Open No. 2008-74832, Japanese Patent No. 3982770, Japanese Patent No. 3801386, WO2005 / 028465, WO2003 / 042203, Japanese Patent Application Laid-Open No. 2005-289812, Japanese Patent Application No. 2005-289870. , JP 2005-112772, Japanese Patent No. 3522189, WO 2002/090342 pamphlet, Japanese Patent No. 3471107, JP 2003-277181, WO 2001/0608. No. 11 pamphlet, WO2000 / 071544, WO2005 / 028465 pamphlet, WO2011 / 16582 pamphlet, WO2011 / 034202 pamphlet, WO2012 / 121414 pamphlet, WO2013 / 042800 pamphlet and the like can be used.

  Among these photochromic compounds, 1 is a chromene compound having an indeno [2,1-f] naphtho [1,2-b] pyran skeleton from the viewpoint of photochromic properties such as color density, initial coloring, durability, and fading speed. It is more preferable to use more than one type. Further, among these chromene compounds, compounds having a molecular weight of 540 or more are preferable because they are particularly excellent in color density and fading speed.

  In the present invention, the photochromic compound used for the first photochromic layer and the other photochromic layer may be selected from the photochromic compounds as described above. If the photochromic characteristics of the solution in which the photochromic compound is dissolved are confirmed, the photochromic compound used for the first photochromic layer and other photochromic layers can be easily selected. At that time, in the characteristics of the photochromic compound blended in each layer, the difference in fading half-life is 20 to 100 sec. It is preferable to select a combination of photochromic compounds (a combination of photochromic compositions containing a plurality of photochromic compounds in some cases) such that the difference in absorption edge is 0 to 50 nm and the difference in maximum absorption wavelength is 50 nm or less.

  Among them, as the photochromic compound contained in the other photochromic layer, which has a fast fading half-life, a compound represented by the following formula (1) is preferable. By using a compound represented by the following formula (1), the obtained optical article can have a higher color density and a faster half-life.

here,
R ^{1 to} R ⁴ are a hydroxyl group, an alkyl group, a haloalkyl group, a cycloalkyl group, an alkoxy group, an amino group, a heterocyclic group that includes a ring nitrogen atom and is bonded to the benzene ring to which the nitrogen atom is bonded, cyano Group, nitro group, formyl group, hydroxycarbonyl group, alkylcarbonyl group, alkoxycarbonyl group, halogen atom, aralkyl group, aralkoxy group, aryloxy group, aryl group, heteroaryl group, alkylthio group, cycloalkylthio group, arylthio group, A heteroarylthio group,
R ^{1 to} R ⁴ may be the same or different from each other, and R ¹ and R ² may combine to form a ring,
C ^* is a spiro carbon atom,
Following formula

The spiro ring A shown by is any one of the following formulae.

  In particular, as a particularly suitable compound contained in another photochromic layer,

(A chromene compound having an indeno [2,1-f] naphtho [1,2-b] pyran skeleton).

(Radical polymerizable component)
In the present invention, the type of the resin matrix forming the photochromic layer is not particularly limited as long as it includes a photochromic compound and has a photochromic property, and known thermoplastic and thermosetting resins can be used without limitation. . The thermosetting resin is composed of a thermosetting resin obtained by polymerizing and curing a composition (photochromic curable composition) containing a radical polymerizable component and a photochromic compound from the viewpoint of excellent photochromic properties. A layer is preferred.

As a radically polymerizable component suitably used for the photochromic curable composition, a known (meth) acrylic monomer can be used without particular limitation. In particular,
Trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane tetramethacrylate, tetramethylolmethane tetraacrylate, trimethylolpropane triethylene glycol trimethacrylate, trimethylolpropane triethylene Trifunctional monomers such as glycol triacrylate,
Ditrimethylolpropane tetramethacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, bisphenol A dimethacrylate, 2,2-bis (4-methacryloyloxyethoxyphenyl) propane, 2,2-bis (4- Methacryloyloxypolyethyleneglycolphenyl) propane, 2,2-bis (4-methacryloyloxypolyethyleneglycolphenyl) propane having an average molecular weight of 804, 2,2-bis (4-acryloyloxypolyethyleneglycolphenyl) propane having an average molecular weight of 776, average molecular weight 468 methoxy polyethylene glycol methacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, Tetraethylene glycol dimethacrylate, pentaethylene glycol dimethacrylate, pentapropylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, pentaethylene glycol diacrylate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate Acrylate, pentapropylene glycol diacrylate, polyethylene glycol dimethacrylate having an average molecular weight of 330, polyethylene glycol dimethacrylate having an average molecular weight of 536, polytetramethylene glycol dimethacrylate having an average molecular weight of 736, tripropylene glycol dimethacrylate, tetrapropylene glycol dimethacrylate Polypropylene glycol dimethacrylate having an average molecular weight of 536, polyethylene glycol diacrylate having an average molecular weight of 258, polyethylene glycol diacrylate having an average molecular weight of 308, polyethylene glycol diacrylate having an average molecular weight of 508, polyethylene glycol diacrylate having an average molecular weight of 708, polycarbonate diol, Bifunctional monomer such as polycarbonate di (meth) acrylate, which is a reaction product with (meth) acrylic acid. Polyfunctional urethane (meth) having 4 or more functionalities such as urethane oligomer tetraacrylate, urethane oligomer hexamethacrylate, urethane oligomer hexaacrylate. Acrylate,
Polyfunctional polyester (meth) acrylate such as polyester oligomer hexaacrylate,
A silsesquioxane monomer having a (meth) acrylic group and having various structures such as cage, ladder, and random,
Examples thereof include monofunctional monomers having one (meth) acryl group such as 2-isocyanatoethyl methacrylate, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and glycidyl methacrylate.

  These radically polymerizable monomers are preferably used in an appropriate mixture of two or more for the purpose of obtaining desired photochromic properties and film hardness. Among these, it is preferable to employ the photochromic curable composition described in Patent Document 1, Patent Document 2, or JP-A-2015-025063.

  In addition to the above radical polymerizable components, polymerizable monomers such as vinyl monomers can also be added. As the vinyl monomer, known compounds can be used without any limitation, but among them, compounding a compound that acts as a polymerization regulator is suitable for improving the moldability of the photochromic curable composition. Specific examples of the vinyl monomer include α-methylstyrene and α-methylstyrene dimer, and it is particularly preferable to combine α-methylstyrene and α-methylstyrene dimer.

(Other ingredients)
A photochromic curable composition for forming a photochromic layer or a photochromic composition includes a silicone-based surfactant having a silicone chain (polyalkylsiloxane unit) as a hydrophobic group, a release agent, an ultraviolet absorber, and an infrared absorber. , UV stabilizers, antioxidants, anti-coloring agents, antistatic agents, fluorescent dyes, dyes, pigments, fragrances and other various stabilizers, additives, and polymerization regulators can be contained as necessary.

  Among these, it is preferable to mix and use an ultraviolet stabilizer because the durability of the photochromic compound can be further improved. Examples of UV stabilizers include hindered amine light stabilizers such as bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, and hinders such as 2,6-di-t-butyl-4-methyl-phenol. A dophenol antioxidant and a sulfur type antioxidant can be used conveniently.

(Method for forming photochromic layer)
A method for forming a photochromic layer (including the first and other photochromic layers) using the photochromic curable composition is not particularly limited, and a known method can be adopted. Specifically, a layer made of a photochromic curable composition may be present on the optical substrate, and the curable composition may be polymerized and cured. As a method for polymerizing the photochromic curable composition, it can be carried out by heat, irradiation with ultraviolet rays (UV rays), α rays, β rays, γ rays, or a combination of both. Under the present circumstances, it is preferable to mix | blend radical polymerization initiators, such as the following thermal polymerization initiator and a photoinitiator, with a photochromic curable composition.

  In this invention, when using a polymerization initiator, the usage-amount of the polymerization initiator is preferably 0.001-10 mass with respect to 100 mass parts of all radical polymerizable monomers contained in a photochromic curable composition. Part, more preferably in the range of 0.01 to 5 parts by mass.

  Examples of typical polymerization initiators include thermal polymerization initiators such as diacyl peroxides such as benzoyl peroxide; peroxyesters such as t-butylperoxy-2-ethylhexanate; diisopropyl peroxydicarbonate and the like. And azo compounds such as azobisisobutyronitrile.

  As the photopolymerization initiator, compounds such as acetophenone and acylphosphine can be employed. Specifically, benzophenone; acetophenone compounds such as 2,2-dimethoxy-1,2-diphenylethane-1-one; α-dicarbonyl compounds such as 1,2-diphenylethanedione; 2,6-dimethyl Acylphosphine oxide compounds such as benzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; 1,2-octanedione-1- [4- (phenylthio) -2- ( O-benzoyloxime)] and the like.

  These polymerization initiators may be used alone or in combination of two or more.

  Moreover, a thermal polymerization initiator and a photopolymerization initiator can be used in combination. When a photopolymerization initiator is used, a known polymerization accelerator such as a tertiary amine can be used in combination. When employing a two-stage polymerization method, it is preferable to blend a thermal polymerization initiator, and when employing a coating method, it is preferable to blend a photopolymerization initiator.

  In the present invention, the above radical polymerizable component may be appropriately selected so that a photochromic layer satisfying desired physical properties can be formed. For example, for the purpose of increasing the surface hardness of the optical article, the film hardness of the other photochromic layer can be set higher than that of the first photochromic layer by adjusting the type and blending amount of the resin matrix and various additives. Although the photobleaching half-life of the photochromic layer can be adjusted depending on the difference in radically polymerizable components, it is easier to adjust the photobleaching half-life by changing the photochromic compound in the coating layer, and productivity can be improved. Can be improved. Therefore, in the first photochromic layer and other photochromic layers, it is preferable that the radical polymerization components that form these photochromic layers have the same constituent components.

(Optical substrate)
In this invention, it can be set as the optical article which has a photochromic layer on an optical base material. The optical substrate that can be used in the present invention is not particularly limited as long as it is a substrate having optical transparency. Specific examples include known optical substrates such as glass and plastic lens substrates, window glass for houses and automobiles, and the use of plastic lens substrates is particularly suitable. Plastic lens base materials include thermoplastic resin lenses such as (meth) acrylic resins and polycarbonate resins; cross-links such as polyfunctional (meth) acrylic resins, allyl resins, thiourethane resins, urethane resins, and thioepoxy resins Well-known lenses that are currently used as plastic lenses, such as plastic resin lenses, can be used. Further, the present invention can also be applied to a plastic lens substrate in which a hard coat layer or the like is laminated on these plastic lens substrates.

  The shape of the plastic lens substrate used in the present invention is not particularly limited, and can be applied to a known shape. The plastic lens substrate has various shapes depending on the visual acuity of the user, the shape of the glass mold when the plastic lens substrate is molded, the productivity, and the like. For example, the lens is a minus lens having a thin center as a myopic lens and a thickness at the edge, and a plus lens having a thick center and a thin edge as a distance lens.

  The optical base material may be subjected to chemical treatment with an alkaline solution, an acid solution, or the like, or physical treatment such as corona discharge, plasma discharge, or polishing in order to improve adhesion with the photochromic layer. Among them, a lens substrate having a primer coat layer as an adhesive layer can be particularly preferably used. For example, as shown in FIG. 2, an optical article in which a primer coat layer 9 is formed on an optical substrate 6 and a first photochromic layer 7 and another photochromic layer 8 are laminated thereon in this order can also be obtained. .

  As the primer coat layer, a known polyurethane resin can be used. Among them, from the viewpoint of adhesion, a moisture curable polyurethane resin / precursor as described in Japanese Patent No. 4405833, or Japanese Patent No. 5016266, Japanese Patent No. 5084727 A primer coat layer made of a water-dispersed urethane emulsion as described above is preferable.

  In the present invention, a photochromic lens substrate manufactured by a kneading method, an in-vibration method or the like can be used as the optical substrate. In this case, the photochromic lens substrate can be regarded as one of the photochromic layers of the present invention. Therefore, the optical article of the present invention can be obtained by forming on the photochromic lens substrate at least one photochromic layer having a fading half-life faster than that of the photochromic lens substrate.

(Method for manufacturing optical article)
Next, the method for producing an optical article of the present invention will be specifically described. First, a method for forming a photochromic layer on an optical substrate will be specifically described.

  When the photochromic curable composition is thermally polymerized, the temperature among the polymerization conditions particularly affects the properties of the resulting photochromic layer. This temperature condition is affected by the type and amount of the thermal polymerization initiator and the type of monomer, so it cannot be limited in general, but in general, the polymerization is started at a relatively low temperature, and the temperature is slowly increased. It is preferable to perform so-called taper type polymerization, which is cured at a high temperature at the end. Since the polymerization time varies depending on various factors as well as the temperature, it is preferable to determine the optimal time according to these conditions in advance. The conditions are preferably selected so that the polymerization is completed in 2 to 24 hours.

  Specific methods for forming the photochromic layer include a coating method and a two-stage polymerization method.

Coating method When an optical article is manufactured by the coating method, a photochromic curable composition mixed with a photopolymerization initiator is applied onto an optical substrate by a spin coating method and placed in an inert gas such as nitrogen. After that, a photochromic layer can be formed by performing UV (ultraviolet) irradiation. Furthermore, another photochromic curable composition designed to have a faster fading half-life than the photochromic layer is applied onto the formed photochromic layer, and UV-cured to produce the optical article of the present invention. be able to.

When photopolymerizing the photochromic curable composition, among the polymerization conditions, particularly the UV intensity affects the properties of the resulting photochromic layer. This illuminance condition is unconditionally limited because it is affected by the type and amount of the photopolymerization initiator and the type of monomer, but in general, UV light of 50 to 500 mW / cm ² at a wavelength of 365 nm is reduced to 0.0. It is preferable to select conditions so that light is irradiated in a time of 5 to 5 minutes.

  As described above, in consideration of productivity, it is preferable to directly stack another photochromic layer on the first photochromic layer. In this case, when the first photochromic layer is formed, the UV irradiation time is set to be shorter than usual, for example, so that the semi-cured state is formed. It can also be cured. In the formation of the first photochromic layer, even if it is cured from a semi-cured state, the final half-life of the cured product (first photochromic layer) is almost the same as that of the cured state without being semi-cured. . This is because the fading half-life of the first photochromic layer obtained by removing the other photochromic layer from the optical article obtained by simultaneously curing the first photochromic layer in the semi-cured state and the other photochromic layer is reduced. This can be confirmed from the fact that the first photochromic layer obtained by direct curing is not different from the fading half-life. By adopting the curing method as described above, the adhesion between the first photochromic layer and the other photochromic layer can be improved.

  In addition, for the purpose of improving the adhesion between the first photochromic layer and another photochromic layer, the same chemical treatment and / or chemical treatment as that of the optical substrate can be applied after the formation of the first photochromic layer. .

  By the method as described above, the first photochromic layer and other photochromic layers can be formed on the optical substrate. In the method, the example in which the first photochromic layer is formed directly on the optical substrate and the other photochromic layer is formed directly on the first photochromic layer has been described. In the present invention, between the optical substrate and the first photochromic layer, between the first photochromic layer and the other photochromic layer, other layers, for example, for improving adhesion, impact resistance, and scratch resistance. A primer coat layer and a hard coat layer can also be formed. Among these, it is preferable to form a primer coat layer.

  In the case of producing an optical article by the coating method, in addition to the above method, in order to improve the adhesion of the photochromic layer, it can be heat-treated at a temperature range of 80 to 120 ° C. for about 0.5 to 5 hours. By such heat treatment, for example, an optical article composed of an optical substrate / primer coat layer formed as necessary / first photochromic layer / primer coat layer formed as necessary / other photochromic layers The adhesion of each photochromic layer can be improved. The thickness of the photochromic layer formed by the coating method is not particularly limited, but it is preferable that all the photochromic layers are combined to be 10 to 70 μm.

Two-stage polymerization method When a photochromic layer is formed by the two-stage polymerization method, a thermal polymerization initiator is blended in the gap formed by the glass mold and the optical substrate held by an elastomer gasket, spacer, or adhesive tape. There is cast polymerization in which a photochromic curable composition is injected, polymerized and cured in an air furnace, and then the laminate is removed from the glass mold. In the case of using a photopolymerization initiator, UV irradiation may be performed for the entire glass mold, and then the cured body may be removed from the glass mold. The temperature at the time of polymerization and curing is not particularly limited, but in the case of thermal polymerization, it is preferable to change the temperature in the range of 20 to 120 ° C. Moreover, in the case of photopolymerization, it is preferable to heat-process for about 0.5 to 5 hours in the temperature range of 80-120 degreeC after photopolymerization.

  Furthermore, using the optical base material on which the photochromic layer produced above is formed, any one of the above methods is repeated, and the photochromic layer (first photochromic layer) has a fading half-life longer than that of the first photochromic layer. By forming another fast photochromic layer, the optical article of the present invention can be produced. When another photochromic layer is directly laminated on the first photochromic layer, the same chemical treatment and / or chemical treatment as the optical substrate is performed after the first photochromic layer is formed for the purpose of improving adhesion. It can also be applied.

  The thickness of the photochromic layer formed by the two-stage polymerization method is not particularly limited, but it is preferable that all the photochromic layers are combined to be 100 to 1000 μm.

  The optical article of the present invention in which a photochromic layer is formed on an optical substrate as described above can be made into an optical article having excellent photochromic properties, high color density, and fast fading speed.

(Post-processing of optical articles)
Furthermore, the optical article obtained by the above method can be subjected to the following treatments depending on its application. That is, dyeing using dyes such as disperse dyes, silane coupling agents, hard coating agents mainly composed of sols such as silicon, zirconium, antimony, aluminum, tin, and tungsten, and SiO ₂ , TiO ₂ , ZrO _2, etc. It is also possible to perform processing and secondary treatment such as antireflection treatment and antistatic treatment by vapor deposition of a metal oxide thin film or application of an organic polymer thin film.

  Next, the present invention will be described in detail using examples and comparative examples, but the present invention is not limited to the examples. In addition, the used compound used by the present Example is as follows.

(Radical polymerizable component)
14G: Polyethylene glycol dimethacrylate (the average chain length of the ethylene glycol chain is 14 and the average molecular weight is 736).
BPE500: 2,2-bis [4- (methacryloxy polyethoxy) phenyl] propane (average chain length of ethylene glycol chain is 10 and average molecular weight is 804).
MA1: γ-methacryloxypropyltrimethoxysilane.
A-PC: esterified product of polyalkylene carbonate diol and acrylic acid mainly composed of pentanediol and hexanediol (average molecular weight 640)
TMPT: trimethylolpropane trimethacrylate.
GMA: glycidyl methacrylate.

  (Photochromic compound)

Other compounding agents (additives)
Stabilizer HALS: Bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (molecular weight 508).
HP: Ethylene bis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate] (Irganox 245, manufactured by Ciba Specialty Chemicals).

Photopolymerization initiator PI: phenylbis (2,4,6-trimethylbenzoyl) -phosphine oxide (trade name: Irgacure 819, manufactured by BASF).

Primer composition PR1: Water-dispersed urethane emulsion (product name: NJ-321A, manufactured by Tokuyama Corporation).

Evaluation of Photochromic Properties The photochromic properties of the photochromic layer described below and the photochromic properties of the obtained photochromic optical article were evaluated as follows. Using a photochromic layer and an optical article having a photochromic layer as a sample, a Xenon lamp L-2480 (300 W) SHL-100 manufactured by Hamamatsu Photonics Co., Ltd. is passed through an aeromass filter (manufactured by Corning) at 23 ° C. ± 1 ° C. The polymer was irradiated with a beam intensity of 365 nm = 2.4 mW / cm ² and 245 nm = 24 μW / cm ² for 300 seconds to develop a color, and the photochromic characteristics of the laminate were measured. Each photochromic characteristic was evaluated by the following method.

  1) Maximum absorption wavelength (λmax): The maximum absorption wavelength after color development determined by a spectrophotometer manufactured by Otsuka Electronics Co., Ltd. (instant multichannel photodetector MCPD3000). The maximum absorption wavelength is related to the color tone at the time of color development.

  2) Color density {ε (300) −ε (0)}: between the absorbance {ε (300)} after light irradiation for 300 seconds and the absorbance {ε (0)} before light irradiation at the maximum absorption wavelength. difference. It can be said that the higher this value, the better the photochromic characteristics.

  3) Fading half-life [t1 / 2 (sec.)]: When light irradiation is stopped after light irradiation for 300 seconds, the absorbance at the maximum absorption wavelength of the sample is {ε (300) −ε (0)}. Time required to drop to 1/2 of The shorter this time, the quicker the color disappears, and it can be said that the photochromic properties are excellent.

4) Measurement of absorption edge The transmittance spectrum of the sample (photochromic layer) before light irradiation was measured under the same conditions as in the above apparatus. In the transmittance spectrum, the wavelength at which the transmittance was 50% was read and used as the absorption edge of the photochromic layer.

Production Example Preparation of Photochromic Curable Composition (Z1) Polyethylene glycol dimethacrylate (average chain length of ethylene glycol chain is 14, average molecular weight is 736) 30 parts by mass, BPE500: 2,2-bis [4- (methacryloxy) -Polyethoxy) phenyl] propane (average chain length of ethylene glycol chain is 10 and average molecular weight is 804) 30 parts by mass, esterified product of polyalkylene carbonate diol and acrylic acid mainly composed of pentanediol and hexanediol ( Average molecular weight 640, (meth) acrylic equivalent 320) 10 parts by mass, trimethylolpropane trimethacrylate 29 parts by mass, glycidyl methacrylate 1 part by mass, and photochromic compound PC1 1.0 part by mass, PC2 2.5 parts by mass At 70 ° C Stirred and mixed for 5 minutes to dissolve the photochromic compound. After cooling to room temperature, 6.5 parts by mass of γ-methacryloxypropyltrimethoxysilane, stabilizer: 3 parts by mass of HALS, 3 parts by mass of HP, 0.3 parts by mass of PI as a polymerization initiator, and Toray as a leveling agent Dow Corning Co., Ltd. L7001 0.1 mass part was added, and the photochromic curable composition (Z1) used for a coating method was obtained. Table 1 shows the blending amounts of the photochromic compounds.

Preparation of photochromic curable compositions (Z2) to (Z9) Photochromic curing was carried out in the same manner as the photochromic curable composition (Z1) except that the types and blending amounts of the photochromic compounds shown in Table 1 were used. Sex compositions (Z2) to (Z9) were prepared. (Z4), (Z5), and (Z6) correspond to compositions in which (Z1) and (Z3) are mixed at a ratio of 1: 3, 1: 1, and 3: 1, respectively (Z7), (Z8) and (Z9) correspond to compositions in which (Z2) and (Z3) are mixed at a ratio of 1: 3, 1: 1, and 3: 1, respectively.

Characteristic evaluation of photochromic layer composed of Z1 to Z9 Using a spin coater (1H-DX2, manufactured by MIKASA), water-dispersed urethane emulsion (product) on the surface of an allyl plastic lens substrate having a center thickness of 2 mm and a refractive index of 1.50 Name: NJ-321A, manufactured by Tokuyama Co., Ltd., and pure water was added to adjust the solid content concentration to 35%) for 15 seconds at a rotation speed of 70 rpm, followed by spin coating at 1500 to 2000 rpm for 4 seconds, and 15 minutes Dried at room temperature. At this time, the spin conditions were adjusted so that the thickness of the dried primer layer was 4 μm. Thereafter, about 2 g of each of the photochromic coating compositions (Z1 to Z9) prepared by the above method was spin-coated so that the cured film thicknesses were 15, 20, and 25 μm, and the output was 200 mW / cm ² in a nitrogen gas atmosphere. Using a metal halide lamp, light was irradiated for 90 seconds to cure the coating film. Thereafter, the mixture was further heated at 100 ° C. for 1 hour to form photochromic layers each consisting of Z1 to Z9. The photochromic characteristics of these photochromic layers were as follows. The results are summarized in Table 2. FIG. 6 shows a transmittance spectrum (Z1 thickness 20 μm, Z2 thickness 20 μm, Z3 thickness 20 μm) before light irradiation.

Example 1
As an optical substrate, an allyl plastic lens having a center thickness of 2 mm and a refractive index of 1.50 was prepared. The allylic plastic lens was previously subjected to alkali etching at 50 ° C. for 5 minutes using a 10% aqueous sodium hydroxide solution, and then thoroughly washed with distilled water.

  Using a spin coater (1H-DX2, manufactured by MIKASA), a water-dispersed urethane emulsion (product name: NJ-321A, manufactured by Tokuyama Co., Ltd., pure water is added to the surface of the plastic lens to obtain a solid content concentration. Was adjusted at 35 rpm for 15 seconds, followed by spin coating at 1500 to 2000 rpm for 4 seconds and dried at room temperature for 15 minutes. At this time, the spin conditions were adjusted so that the thickness of the dried primer layer was 4 μm.

Formation of the first photochromic layer Thereafter, about 2 g of the photochromic curable composition (Z1) obtained above was cured at a rotational speed of 100 rpm for 40 seconds, and then at 2000 rpm for 3 to 15 seconds. Spin coating was performed so that the thickness was 15 μm. The lens having the surface coated with the photochromic curable composition (Z1) is irradiated with light for 10 seconds in a nitrogen gas atmosphere using a metal halide lamp having an output of 200 mW / cm ² to temporarily cure the coating film. I let you.

Formation of another photochromic layer Further, about 2 g of the photochromic curable composition (Z3) was applied at a rotation speed of 100 rpm for 40 seconds, and then at 1200 rpm for 3 to 15 seconds, so that the film thickness of the photochromic layer after curing was 25 μm (2 The total thickness of the photochromic layers was 40 μm. Next, using a metal halide lamp with an output of 200 mW / cm ² in a nitrogen gas atmosphere, light was irradiated for 90 seconds to cure the coating film.

  Thereafter, the product was further heated at 100 ° C. for 1 hour to produce an optical article having two photochromic layers.

  The obtained optical article was evaluated for photochromic properties by the method described in the method for evaluating photochromic properties. As a result, it had photochromic characteristics with a maximum absorption wavelength of 575 nm, a color density of 1.10, and a fading half-life of 60 seconds.

Example 2-13, Comparative Example 1-5
Optical articles were prepared and evaluated in the same manner as in Example 1 except for the photochromic curable compositions shown in Tables 3 and 4. The evaluation results are shown in Tables 3 and 4. The results of plotting the color density obtained in Example 1-3 and Comparative Example 1-8 against the fading half-life are shown in FIG. Moreover, the result of having plotted the color density obtained in Example 4-6 and Comparative Example 9-16 against the fading half-life is shown in FIG.

  As is clear from FIG. 4, in Comparative Example 1-5 composed of a single photochromic layer, the color density changes almost linearly with respect to the fading half-life, whereas in Example 1-3, The plot is located above the line. That is, when compared with the same fading half-life, Example 1-3 shows that the color density is higher than that in the case of a single photochromic layer. At this time, in Example 1-3, as shown in Table 2, the other photochromic layer (photochromic curable composition: Z3) was compared with the first photochromic layer (photochromic curable composition: Z1). Fast color fading half-life. On the other hand, in Comparative Example 6-8 in which the order of the photochromic layers is reversed, since it is plotted below the line of Comparative Example 1-5, when compared with the same fading half-life, from a single photochromic layer It can be seen that the color density is even lower than in this case.

  Similarly, as is clear from FIG. 5, Example 4-6 is compared with Comparative Example 9-12 composed of a single photochromic layer and Comparative Example 13-15 in which the order of the photochromic layers is reversed. When compared with the same fading half-life, it can be seen that the color density increases.

  Moreover, as shown in Table 2 and FIG. 6, in the case of Example 1-3, the other photochromic layer has a shorter absorption edge than the first photochromic layer. For this reason, compared with Example 4-6 in which the absorption edges of the other photochromic layers and the first photochromic layer are substantially the same, Example 1-3 has a greater effect of multilayering the photochromic layer. Conceivable.

  From the above, it can be seen that the optical article of the present invention has a high color density and a fast fading rate.

DESCRIPTION OF SYMBOLS 1 Light quantity of the excitation light which injects into a photochromic layer 2 Other photochromic layer 3 First photochromic layer 4 Light quantity absorbed in the upper photochromic layer (other photochromic layer) 2 Lower photochromic layer (first photochromic layer) ) Amount of light absorbed in 3 Optical substrate 7 First photochromic layer 8 Other photochromic layer 9 Primer coat layer 10 Direction of incident light 11 Color development density change of dye having slow fading half-life 12 Dye having fast fading half-life Color density change of

Claims (4)

An optical article having a plurality of photochromic layers containing a photochromic compound,
When the photochromic layer located farthest from the light incident side is the first photochromic layer,
An optical article characterized in that the fading half-life of the first photochromic layer is slower than the fading half-life of other photochromic layers.   The optical article according to claim 1, wherein an absorption edge of the first photochromic layer has a shorter wavelength than an absorption edge of another photochromic layer.   The optical article according to claim 1, wherein the optical article has a first photochromic layer and another photochromic layer on the optical substrate.   The optical article according to claim 3, wherein the first photochromic layer is present on an optical base on which light is incident, and another photochromic layer is laminated on the first photochromic layer.

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