Photochromic substance and method for producing same
09663398 ยท 2017-05-30
Assignee
Inventors
Cpc classification
C03C2204/00
CHEMISTRY; METALLURGY
C03C2214/17
CHEMISTRY; METALLURGY
International classification
C03C14/00
CHEMISTRY; METALLURGY
Abstract
Provided is a photochromic substance that has lower toxicity, exhibits good sensitivity in a visible light region, changes color deeply, has slow speed of color fading, has chemical and thermal stability, and has good durability. The photochromic substance has a composition represented by the formula:
Ba.sub.(a-b)Ca.sub.bMg.sub.cSi.sub.dO.sub.e:Fe.sub.fM.sub.gM.sub.h where 1.8a2.2, 0b0.1, 1.4c3.5, 1.8d2.2, e=(a+c+2d), 0.0001f, 0.0001g, 0h, M is at least one of Al and Eu, and M is at least one element selected from the group consisting of Na, K, Nd, Li, S, C, Ti, V, Mn, Cr, Cu, Ni, Co, Ge, Zn, Ga, Zr, Y, Nb, In, Ag, Mo, Sn, Sb, Bi, Ta, W, La, Ce, Pr, Nd, Sm, Gd, Er, Ho, Tb, Tm, Yb, Lu, P, Cd, and Pb.
Claims
1. A photochromic substance having a composition represented by the following formula (1):
Ba.sub.(a-b)Ca.sub.bMg.sub.cSi.sub.dO.sub.e:Fe.sub.fM.sub.g(1) where 1.8a2.2, 0b0.1, 1.4c3.5, 1.8d2.2, e=(a+c+2d), 0.0001f, 0.0001g, and M is.
2. The photochromic substance according to claim 1, wherein in the formula (1) 0.001g0.012.
3. A photochromic material comprising a photochromic substance as set forth in claim 1.
4. A method for producing a photochromic substance as set forth in claim 1, comprising the step of burning a mixture of (i) a raw material group including elements constituting the photochromic substance of claim 1 and (ii) boric acid.
5. The method according to claim 4, wherein the step of burning is carried out in a reductive atmosphere.
6. The method according to claim 5, wherein the step of burning is carried out in presence of a hydrogen gas.
Description
BRIEF DESCRIPTION OF DRAWINGS
(1)
(2)
(3)
DESCRIPTION OF EMBODIMENTS
(4) An embodiment of the present invention is described below in detail.
(5) (Photochromic Substance)
(6) A photochromic substance of the present invention has a composition represented by the following formula (1):
Ba.sub.(a-b)Ca.sub.bMg.sub.cSi.sub.dO.sub.e:Fe.sub.fM.sub.gM.sub.h(1)
(7) In the formula (1), M is at least one of Al and Eu. Especially, Al is more preferable since Al is easily available, inexpensive, and has low toxicity unlike rare earthes such as Eu. It is a new finding made by the inventors of the present invention that a photochromic substance that exhibits excellent effects can be obtained by adding Al, which is not a rare earth.
(8) In the formula (1), M is at least one element selected from the group consisting of Na, K, Nd, Li, S, C, Ti, V, Mn, Cr, Cu, Ni, Co, Ge, Zn, Ga, Zr, Y, Nb, In, Ag, Mo, Sn, Sb, Bi, Ta, W, La, Ce, Pr, Nd, Sm, Gd, Er, Ho, Tb, Tm, Yb, Lu, P, Cd, and Pb. It is more preferable that M include at least one of Cu, Ag, and Au, which are Group 11 elements, and it is further more preferable that M includes Cu.
(9) In the formula (1), i.e., in the composition ratio of the photochromic substance, 1.8a2.2, 0b0.1, 1.4c3.5, 1.8d2.2, e=(a+c+2d), 0.0001f, 0.0001g, and 0h.
(10) In the formula (1), 1.9a2.1 is more preferable. Moreover, 0b0.01 is more preferable, 0b0.001 is further more preferable, and b=0 is especially preferable. Moreover, 2.0c3.5 is more preferable, and 2.5c3 is further more preferable. Moreover, 1.9d2.1 is more preferable. Moreover, 0.0005f is more preferable, 0.001f is further more preferable, and 0.002f is especially preferable. Moreover, f2 is more preferable, f1 is further more preferable, f0.5 is especially preferable, and f0.2 is most preferable. Moreover, 0.0005g is more preferable, and 0.001g is further more preferable. Moreover, g0.025 is more preferable, and g0.012 is further more preferable. Moreover, 0.0001h is more preferable, 0.0005h is further more preferable, and 0.001h is especially preferable. Moreover, h0.025 is more preferable, and h0.012 is further more preferable. This makes it possible to provide a photochromic substance that exhibits a higher photochromism property. Furthermore, in the formula (1), it is especially preferable that M is Al and h=0.
(11) The photochromic substance of the present invention that has the above composition is a substance based on barium magnesium silicate. The photochromic substance of the present invention has a tridymite structure, i.e., a structure in which SiO.sub.4 tetrahydrons are connected with each other via their vertexes, and thus forms a three-dimensional tunnel structure. The photochromic substance of the present invention has a structure in which a certain percentage of silicon ions (Si.sup.4+) in the SiO.sub.4 tetrahydrons is replaced with a magnesium ion (Mg.sup.2+) and a barium ion (Ba.sup.2+) and the like are embedded in the three-dimensional tunnel structure.
(12) With the above composition, the photochromic substance of the present invention exhibits a good photochromism property in a visible light region. For example, the photochromic substance of the present invention has a property of changing its color from white to red (pink) upon application of blue light (e.g., light having a wavelength of 405 nm) and a property of changing its color from white to deep red (pink) upon application of ultraviolet light (e.g., light having a wavelength of 365 nm). That is, with the above composition, the photochromic substance of the present invention is controllable as to how deeply its color changes (reflectance), depending on a wavelength of light with which the photochromic substance is irradiated.
(13) In addition, the photochromic substance of the present invention has a property of undergoing color fading and returning to its original color (white), for example, upon application of green light (e.g., light having a wavelength of 532 nm) in a state where the photochromic substance has changed to red or deep red by application of the above light. That is, the photochromic substance of the present invention has a good reversible property. Moreover, the photochromic substance of the present invention has good durability because it observes almost no influence on the color change and color fading even after 10 or more applications of ultraviolet light and green light.
(14) Furthermore, the photochromic substance of the present invention has high resistance to heat in terms of a state of color change caused due to the photochromism property, and can retain the state of color change, for example, up to approximately 100 C. Moreover, once the photochromic substance of the present invention exhibits a photochromism property, the state of color change can be retained for a long period (e.g. several hundred days).
(15) That is, with the composition, the photochromic substance of the present invention has lower toxicity, exhibits good sensitivity in a visible light region, changes color deeply (has lower reflectance), has a slow speed of color fading (has a high capacity of retaining the color change), has chemical and thermal stability, and has good durability.
(16) A photochromic material of the present invention contains the photochromic substance. The photochromic material of the present invention may contain one (1) kind of photochromic substance or may contain plural kinds of photochromic substances that are different from each other in composition. An amount of the photochromic substance contained in the photochromic material is not limited in particular, provided that the photochromic substance can achieve a photochromism property in accordance with application of the photochromic material. Since the photochromic material of the present invention contains the photochromic substance, the photochromic material of the present invention has lower toxicity, exhibits good sensitivity in a visible light region, changes color deeply (has lower reflectance), has a slow speed of color fading (has a high capacity of retaining the color change), has chemical and thermal stability, and has good durability.
(17) Specific examples of the photochromic material encompass various industrial products such as an optical disc (ultrahigh-density memory), an optical switch, optical printing ink, a display, sunglasses, and light control glass.
(18) (Method for Producing Photochromic Substance)
(19) The photochromic substance of the present invention can be produced by a production method including the burning step of burning a mixture of (i) a raw material group including elements constituting the photochromic substance and (ii) boric acid (B(OH).sub.3). The mixture may further contain, in addition to the raw material group and boric acid, other compounds such as boron oxide, boron fluoride, boron carbide, and magnesium fluoride, as long as these compounds do not inhibit the photochromism property.
(20) The raw material group is more specifically described below. Examples of a raw material containing Ba encompass barium carbonate, barium sulfate, barium oxide, barium nitrate, barium hydroxide, barium silicide, and barium borate. Examples of a raw material containing Ca encompass calcium carbonate, calcium oxide, calcium nitrate, calcium hydroxide, calcium borate, and calcium acetate. Examples of a raw material containing Mg encompass magnesium carbonate. Examples of a raw material containing Si encompass silicon and silicon dioxide. Examples of a raw material containing Fe encompass iron oxides having respective oxidation numbers. Examples of a raw material containing Eu encompass europium oxides having respective oxidation numbers and europium nitrate. Examples of a raw material containing Al encompass aluminum oxide and aluminum acetate. Examples of a raw material containing an element represented by M in the formula (1) encompass oxides, hydroxides, carbonates, sulfates, and nitrates of the element. The oxygen (O) constituting the photochromic substance of the present invention is derived from oxygen contained in oxides and hydroxides in the raw material group. That is, the oxides and hydroxides in the raw material group are also raw materials containing O. It is therefore preferable that at least one of the raw materials in the raw material group contains O.
(21) By adjusting an amount of the raw materials contained (blended) in the mixture, it is possible to produce a photochromic substance having a desired composition.
(22) Boric acid is added to the raw material group in order that the raw material group is burnt in the burning step in a reductive atmosphere. An amount of boric acid in the mixture is not limited in particular, but is preferably in a range from 2 mol % to 10 mol % with respect to Ba contained in a Ba-containing raw material in the raw material group. That is, it is preferable that the mixture be prepared by mixing, with the raw material group, boric acid of an amount in a range from 2 mol % to 10 mol % with respect to Ba. Through the burning, boric acid evaporates as boric oxide. Accordingly, the photochromic substance contains substantially no boron.
(23) The mixture may further contain a solvent such as ethyl alcohol so that the raw material group and boric acid are mixed more uniformly. A method of mixing the raw material group, boric acid, solvent, and the like is not limited in particular, provided that they can be mixed as uniformly as possible.
(24) The burning step of burning the mixture is more preferably carried out in a reductive atmosphere, further more preferably in the presence of a hydrogen gas. One specific example of a burning method is a method of burning the mixture in a flow of a mixture gas of an inactive gas such as an argon gas and a reducing gas such as a hydrogen gas. A concentration of the hydrogen gas in the mixture gas is preferably in a range from 2% by volume to 10% by volume. One example of a burning condition for the burning step is 1200 C. to 1400 C. and 1 to 5 hours. Note, however, that the burning condition such as a burning temperature, a burning time, and a flow amount of the mixture gas is not limited in particular, and can be set as appropriate to an optimum condition in accordance with the composition of the photochromic substance. Furthermore, a rate of temperature increase (heating rate) and a rate of temperature drop (cooling rate) are not limited in particular, and can be set as appropriate to an optimum condition. As a burning device for the burning step, a commercially available device can be used.
(25) It is estimated that by thus burning the mixture preferably in a reductive atmosphere, an oxygen defect occurs in a crystal structure of the photochromic substance, which is a burnt product, and that the oxygen defect is involved with the photochromism property. It is therefore possible to produce a photochromic substance that exhibits a higher photochromism property.
EXAMPLES
(26) The present invention is described below in more detail based on Examples. Note, however, that the present invention is not limited to the Examples below.
Example 1
Ba2Mg2.5Si2O8.25: Fe0.004Al0.001
(27) As a raw material group, powders of barium carbonate (BaCO.sub.3), magnesium carbonate (MgCO.sub.3), silicon dioxide (SiO.sub.2), ferric oxide (Fe.sub.2O.sub.3), and aluminum oxide (Al.sub.2O.sub.3) were taken so that a molar ratio of the metal components was 2:2.5:2:0.004:0.001. To the raw material group, boric acid was added in an amount of 10 mol % with respect to Ba contained in the raw material group and ethyl alcohol was added (approximately 30 mL to 80 mL with respect to the total amount (approximately 8 g) of the raw material group and the boric acid). They were fully mixed to obtain a mixture.
(28) After the mixture was dried naturally, a pellet having a diameter of 20 mm and a thickness of 5 mm was prepared from the mixture. The pellet was burnt with the use of an electrical furnace at 1300 C. for 4 hours in a mixture gas containing argon (95% by volume) and hydrogen (5% by volume). In this way, a sample A having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.001 was prepared.
(29) The sample A was irradiated, at room temperature (25 C.) for 3 minutes, with visible light (7.2 mW/cm.sup.2) having a wavelength of 405 nm. As a result, the sample A underwent a color change from white to red. It was thus confirmed that the sample A exhibited photochromism. Furthermore, the sample A was irradiated with visible light (output: 556 mW/cm.sup.2) having a wavelength of 405 nm with use of a laser, and 3 minutes later from the irradiation, its reflectance of light having a wavelength of 523 nm, which is a maximum value in an absorbance spectrum of the sample A, was measured at room temperature (25 C.) in an atmosphere with the use of an ultraviolet visible spectrometer to evaluate a photochromism property of the sample A. The measurement was carried out under the condition that a measurement range be 500 nm to 600 nm, a slit width be 1 nm, and a scanning speed be 100 nm/min, and an integrating sphere was used. As a result of the measurement, it was revealed that the reflectance was 13.55%.
Example 2
Ba2Mg2.5Si2O8.25: Fe0.004Al0.002
(30) Similar processes to those of Example 1 were carried out except for that aluminum oxide (Al.sub.2O.sub.3) was taken so that a molar ratio of aluminum is 0.002. A sample B having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.002 was thus prepared. A photochromism property of the sample B was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample B was 12.64%.
Example 3
Ba2Mg2.5Si2O8.25: Fe0.004Al0.004
(31) Similar processes to those of Example 1 were carried out except for that aluminum oxide (Al.sub.2O.sub.3) was taken so that a molar ratio of aluminum is 0.004. A sample C having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.004 was thus prepared. A photochromism property of the sample C was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample C was 12.63%.
(32) Next, the sample C was irradiated with visible light having a wavelength of 405 nm in a similar manner to Example 1, and 4, 7, 14, 22, 31, 59, 71, 80, 107, 125, 163, 232, 292, and 319 days later from the irradiation, its reflectance of light having a wavelength of 523 nm was measured to evaluate time dependency of the photochromism property of the sample C. The result is shown in
Example 4
Ba2Mg2.5Si2O8.25: Fe0.004Al0.006
(33) Similar processes to those of Example 1 were carried out except for that aluminum oxide (Al.sub.2O.sub.3) was taken so that a molar ratio of aluminum is 0.006. A sample D having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.006 was thus prepared. A photochromism property of the sample D was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample D was 12.56%.
Example 5
Ba2Mg2.5Si2O8.25: Fe0.004Al0.012
(34) Similar processes to those of Example 1 were carried out except for that aluminum oxide (Al.sub.2O.sub.3) was taken so that a molar ratio of aluminum is 0.012. A sample E having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25 Fe.sub.0.004Al.sub.0.012 was thus prepared. A photochromism property of the sample E was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample E was 12.51%.
Example 6
Ba2Mg2.5Si2O8.25: Fe0.004Eu0.001
(35) Similar processes to those of Example 1 were carried out except for that europium oxide (Eu.sub.2O.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample F having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Eu.sub.0.001 was thus prepared. A photochromism property of the sample F was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample F was 13.65%.
Example 7
Ba2Mg2.5Si2O8.25: Fe0.004Eu0.001Cu0.001
(36) Similar processes to those of Example 1 were carried out except for that powders of barium carbonate (BaCO.sub.3), magnesium carbonate (MgCO.sub.3), silicon dioxide (SiO.sub.2), ferric oxide (Fe.sub.2O.sub.3), europium oxide (Eu.sub.2O.sub.3), and cupric oxide (CuO) were taken as a raw material group so that a molar ratio of the metal components is 2:2.5:2:0.004:0.001:0.001. A sample G having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Eu.sub.0.001Cu.sub.0.001 was thus prepared. A photochromism property of the sample G was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample G was 13.71%.
Comparative Example 1
Ba2Mg2.5Si2O8.25: Fe0.004
(37) Similar processes to those of Example 1 were carried out except for that powders of barium carbonate (BaCO.sub.3), magnesium carbonate (MgCO.sub.3), silicon dioxide (SiO.sub.2), and ferric oxide (Fe.sub.2O.sub.3) were taken as a raw material group so that a molar ratio of the metal components is 2:2.5:2:0.004. A sample a for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004 was thus prepared. A photochromism property of the sample a was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample a was 13.89%.
(38) Next, the sample a was irradiated with visible light having a wavelength of 405 nm in a similar manner to Example 1, and 4, 7, 14, 22, 31, 59, 71, 80, 107, 125, 163, 232, 292, and 319 days later from the irradiation, its reflectance of light having a wavelength of 523 nm was measured to evaluate time dependency of the photochromism property of the sample a. The result is shown in
Comparative Example 2
Ba2Mg2.5Si2O8.25: Fe0.004Cu0.001
(39) Similar processes to those of Example 1 were carried out except for that cupric oxide (CuO) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample b for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Cu.sub.0.001 was thus prepared. A photochromism property of the sample b was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample b was 14.44%.
Comparative Example 3
Ba2Mg2.5Si2O8.25: Fe0.004Mo0.001
(40) Similar processes to those of Example 1 were carried out except for that molybdenum trioxide (MoO.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample c for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Mo.sub.0.001 was thus prepared. A photochromism property of the sample c was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample c was 14.77%.
Comparative Example 4
Ba2Mg2.5Si2O8.25: Fe0.004Li0.001
(41) Similar processes to those of Example 1 were carried out except for that lithium oxide (Li.sub.2O) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample d for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Li.sub.0.001 was thus prepared. A photochromism property of the sample d was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample d was 15.19%.
Comparative Example 5
Ba2Mg2.5Si2O8.25: Fe0.004Na0.001
(42) Similar processes to those of Example 1 were carried out except for that sodium oxide (Na.sub.2O) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample e for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Na.sub.0.001 was thus prepared. A photochromism property of the sample e was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample e was 15.48%.
Comparative Example 6
Ba2Mg2.5Si2O8.25: Fe0.004P0.001
(43) Similar processes to those of Example 1 were carried out except for that diphosphorus pentaoxide (P.sub.2O.sub.5) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample f for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004P.sub.0.001 was thus prepared. A photochromism property of the sample f was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample f was 15.20%.
Comparative Example 7
Ba2Mg2.5Si2O8.25: Fe0.004S0.001
(44) Similar processes to those of Example 1 were carried out except for that sulfur (S) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample g for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004S.sub.0.001 was thus prepared. A photochromism property of the sample g was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample g was 15.23%.
Comparative Example 8
Ba2Mg2.5Si2O8.25: Fe0.004K0.001
(45) Similar processes to those of Example 1 were carried out except for that potassium oxide (K.sub.2O) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample h for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004K.sub.0.001 was thus prepared. A photochromism property of the sample h was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample h was 25.32%.
Comparative Example 9
Ba2Mg2.5Si2O8.25: Fe0.004Ti0.001
(46) Similar processes to those of Example 1 were carried out except for that titanium dioxide (TiO.sub.2) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample i for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ti.sub.0.001 was thus prepared. A photochromism property of the sample i was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample i was 18.30%.
Comparative Example 10
Ba2Mg2.5Si2O8.25: Fe0.004Cr0.001
(47) Similar processes to those of Example 1 were carried out except for that chromium trioxide (CrO.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample j for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Cr.sub.0.001 was thus prepared. A photochromism property of the sample j was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample j was 14.96%.
Comparative Example 11
Ba2Mg2.5Si2O8.25: Fe0.004V0.001
(48) Similar processes to those of Example 1 were carried out except for that divanadium pentoxide (V.sub.2O.sub.5) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample k for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004V.sub.0.001 was thus prepared. A photochromism property of the sample k was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample k was 16.18%.
Comparative Example 12
Ba2Mg2.5Si2O8.25: Fe0.004Mn0.001
(49) Similar processes to those of Example 1 were carried out except for that manganese monoxide (MnO) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample 1 for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Mn.sub.0.001 was thus prepared. A photochromism property of the sample 1 was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample 1 was 15.51%.
Comparative Example 13
Ba2Mg2.5Si2O8.25: Fe0.004Ni0.001
(50) Similar processes to those of Example 1 were carried out except for that nickel oxide (Ni.sub.2O.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample m for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ni.sub.0.001 was thus prepared. A photochromism property of the sample m was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample m was 18.29%.
Comparative Example 14
Ba2Mg2.5Si2O8.25: Fe0.004Zn0.001
(51) Similar processes to those of Example 1 were carried out except for that zinc oxide (ZnO) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample n for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Zn.sub.0.001 was thus prepared. A photochromism property of the sample n was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample n was 27.66%.
Comparative Example 15
Ba2Mg2.5Si2O8.25: Fe0.004Ga0.001
(52) Similar processes to those of Example 1 were carried out except for that gallium oxide (Ga.sub.2O.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample o for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ga.sub.0.001 was thus prepared. A photochromism property of the sample o was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample o was 15.75%.
Comparative Example 16
Ba2Mg2.5Si2O8.25: Fe0.004Ge0.001
(53) Similar processes to those of Example 1 were carried out except for that germanium dioxide (GeO.sub.2) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample p for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ge.sub.0.001 was thus prepared. A photochromism property of the sample p was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample p was 15.44%.
Comparative Example 17
Ba2Mg2.5Si2O8.25: Fe0.004Y0.001
(54) Similar processes to those of Example 1 were carried out except for that yttrium oxide (Y.sub.2O.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample q for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Y.sub.0.001 was thus prepared. A photochromism property of the sample q was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample q was 14.92%.
Comparative Example 18
Ba2Mg2.5Si2O8.25: Fe0.004Zr0.001
(55) Similar processes to those of Example 1 were carried out except for that zirconium oxide (ZrO.sub.2) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample r for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Zr.sub.0.001 was thus prepared. A photochromism property of the sample r was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample r was 14.60%.
Comparative Example 19
Ba2Mg2.5Si2O8.25: Fe0.004In0.001
(56) Similar processes to those of Example 1 were carried out except for that indium oxide (In.sub.2O.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample s for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004In.sub.0.001 was thus prepared. A photochromism property of the sample s was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample s was 14.84%.
Comparative Example 20
Ba2Mg2.5Si2O8.25: Fe0.004Sn0.001
(57) Similar processes to those of Example 1 were carried out except for that stannic oxide (SnO.sub.2) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample t for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Sn.sub.0.001 was thus prepared. A photochromism property of the sample t was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample t was 14.14%.
Comparative Example 21
Ba2Mg2.5Si2O8.25: Fe0.004Sb0.001
(58) Similar processes to those of Example 1 were carried out except for that antimony pentoxide (Sb.sub.2O.sub.5) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample u for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Sb.sub.0.001 was thus prepared. A photochromism property of the sample u was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample u was 14.36%.
Comparative Example 22
Ba2Mg2.5Si2O8.25: Fe0.004La0.001
(59) Similar processes to those of Example 1 were carried out except for that lanthanum oxide (La.sub.2O.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample v for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004La.sub.0.001 was thus prepared. A photochromism property of the sample v was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample v was 14.39%.
Comparative Example 23
Ba2Mg2.5Si2O8.25: Fe0.004Ta0.001
(60) Similar processes to those of Example 1 were carried out except for that tantalum pentoxide (Ta.sub.2O.sub.5) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample w for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ta.sub.0.001 was thus prepared. A photochromism property of the sample w was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample w was 13.96%.
Comparative Example 24
Ba2Mg2.5Si2O8.25: Fe0.004W0.001
(61) Similar processes to those of Example 1 were carried out except for that tungsten trioxide (WO.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample x for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004W.sub.0.001 was thus prepared. A photochromism property of the sample x was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample x was 15.50%.
Comparative Example 25
Ba2Mg2.5Si2O8.25: Fe0.004Pb0.001
(62) Similar processes to those of Example 1 were carried out except for that lead dioxide (PbO.sub.2) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample y for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Pb.sub.0.001 was thus prepared. A photochromism property of the sample y was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample y was 15.17%.
Comparative Example 26
Ba2Mg2.5Si2O8.25: Fe0.004Bi0.001
(63) Similar processes to those of Example 1 were carried out except for that bismuth oxide (Bi.sub.2O.sub.3) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample z for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Bi.sub.0.001 was thus prepared. A photochromism property of the sample z was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample z was 14.55%.
Comparative Example 27
Ba2Mg2.5Si2O8.25: Fe0.004Nb0.001
(64) Similar processes to those of Example 1 were carried out except for that niobium oxide (Nb.sub.2O.sub.5) was used instead of aluminum oxide (Al.sub.2O.sub.3). A sample aa for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Nb.sub.0.001 was thus prepared. A photochromism property of the sample aa was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample aa was 13.92%.
Comparative Example 28
Ba2Mg2.5Si2O8.25: Fe0.004Eu0.001Cu0.001
(65) Similar processes to those of Example 1 were carried out except for that powders of barium carbonate (BaCO.sub.3), magnesium carbonate (MgCO.sub.3), silicon dioxide (SiO.sub.2), ferric oxide (Fe.sub.2O.sub.3), europium oxide (Eu.sub.2O.sub.3), and cobalt oxide (Co.sub.2O.sub.3) were taken as a raw material group so that a molar ratio of the metal components is 2:2.5:2:0.004:0.001:0.001. A sample ab for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Eu.sub.0.001Co.sub.0.001 was thus prepared. A photochromism property of the sample ab was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample ab was 14.96%.
Comparative Example 29
Ba2Mg2.5Si2O8.25: Eu0.004
(66) Similar processes to those of Example 1 were carried out except for that powders of barium carbonate (BaCO.sub.3), magnesium carbonate (MgCO.sub.3), silicon dioxide (SiO.sub.2), and europium oxide (Eu.sub.2O.sub.3) were taken as a raw material group so that a molar ratio of the metal components is 2:2.5:2:0.004. A sample ac for comparison having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Eu.sub.0.004 was thus prepared. A photochromism property of the sample ac was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample ac was 16.18%.
(67) Next, the sample ac was irradiated with visible light having a wavelength of 405 nm in a similar manner to Example 1, and 4, 7, 14, 22, 31, 59, 71, 80, 107, 125, 163, 232, 292, and 319 days later from the irradiation, its reflectance of light having a wavelength of 523 nm was measured to evaluate time dependency of the photochromism property of the sample ac. The result is shown in
Reference Example 1
Ba2Mg2.5Si2O8.25
(68) Similar processes to those of Example 1 were carried out except for that powders of barium carbonate (BaCO.sub.3), magnesium carbonate (MgCO.sub.3), and silicon dioxide (SiO.sub.2) were taken as a raw material group so that a molar ratio of the metal components is 2:2.5:2. A sample for reference having a composition represented by Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25 was thus prepared. A photochromism property of the sample was evaluated in a similar manner to Example 1. As a result, it was revealed that reflectance of the sample is 27.53%.
(69) Next, the sample was irradiated with visible light having a wavelength of 405 nm in a similar manner to Example 1, and 4, 7, 14, 22, 31, 59, 71, 80, 107, 125, 163, 232, 292, and 319 days later from the irradiation, its reflectance of light having a wavelength of 523 nm was measured to evaluate time dependency of the photochromism property of the sample . The result is shown in
(70) [Discussion]
(71) Table 1 summarizes the results of reflectance (%) of light having a wavelength of 523 nm measured in Examples 1 to 7, Comparative Examples 1 to 29, and Reference Example 1 above.
(72) TABLE-US-00001 TABLE 1 Reflectance Sample Composition Formula (%) Ex. 1 A Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.001 13.55 Ex. 2 B Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.002 12.64 Ex. 3 C Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.004 12.63 Ex. 4 D Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.006 12.56 Ex. 5 E Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Al.sub.0.012 12.51 Ex. 6 F Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Eu.sub.0.001 13.65 Ex. 7 G Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: 13.71 Fe.sub.0.004Eu.sub.0.001Cu.sub.0.001 Com. Ex. 1 a Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004 13.89 Com. Ex. 2 b Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Cu.sub.0.001 14.44 Com. Ex. 3 c Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Mo.sub.0.001 14.77 Com. Ex. 4 d Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Li.sub.0.001 15.19 Com. Ex. 5 e Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Na.sub.0.001 15.48 Com. Ex. 6 f Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004P.sub.0.001 15.20 Com. Ex. 7 g Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004S.sub.0.001 15.23 Com. Ex. 8 h Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004K.sub.0.001 25.32 Com. Ex. 9 i Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ti.sub.0.001 18.30 Com. Ex. 10 j Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Cr.sub.0.001 14.96 Com. Ex. 11 k Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004V.sub.0.001 16.18 Com. Ex. 12 l Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Mn.sub.0.001 15.51 Com. Ex. 13 m Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ni.sub.0.001 18.29 Com. Ex. 14 n Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Zn.sub.0.001 27.66 Com. Ex. 15 o Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ga.sub.0.001 15.75 Com. Ex. 16 p Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ge.sub.0.001 15.44 Com. Ex. 17 q Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Y.sub.0.001 14.92 Com. Ex. 18 r Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Zr.sub.0.001 14.60 Com. Ex. 19 s Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004In.sub.0.001 14.84 Com. Ex. 20 t Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Sn.sub.0.001 14.14 Com. Ex. 21 u Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Sb.sub.0.001 14.36 Com. Ex. 22 v Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004La.sub.0.001 14.39 Com. Ex. 23 w Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Ta.sub.0.001 13.96 Com. Ex. 24 x Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004W.sub.0.001 15.50 Com. Ex. 25 y Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Pb.sub.0.001 15.17 Com. Ex. 26 z Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Bi.sub.0.001 14.55 Com. Ex. 27 aa Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Fe.sub.0.004Nb.sub.0.001 13.92 Com. Ex. 28 ab Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: 14.96 Fe.sub.0.004Eu.sub.0.001Co.sub.0.001 Com. Ex. 29 ac Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25: Eu.sub.0.004 16.18 Ref. Ex. 1 Ba.sub.2Mg.sub.2.5Si.sub.2O.sub.8.25 27.53 Abbreviation: Ex. represents Example, Com. Ex. represents Comparative Example, and Ref. Ex. represents Reference Example.
(73)
(74) As is clear from
(75)
(76) As is clear from
INDUSTRIAL APPLICABILITY
(77) A photochromic substance of the present invention and a method of the present invention for producing the photochromic substance are applicable to various industrial products such as an optical disc (ultrahigh-density memory), an optical switch, optical printing ink, a display, sunglasses, and light control glass.