JPH10168448A - Phosphorescent pigment and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphorescent pigment having a high initial luminance, retaining luminance recognizable with the naked eye for a long time from evening to dawn, being chemically stable and being water-insoluble and having light resistance and to provide a method for producing the same. SOLUTION: This pigment is obtained by sintering a composition consisting essentially of SrCO3 , Al2 O3 , H3 BO3 , Eu2 O3 and Dy2 O3 in the presence of carbon(C) and/or hydrogen(H) and is represented by the formula: Sr(AlB)m On ; EuDy (m is 2, 3 or 4; and n is 4, 5, 6, or 7). It is desirable that this composition contains 30-70wt.% SrCO3 , 20-65wt.% Al2 O3 , 3-12wt.% H3 BO3 , 0.4-1.0wt.% Eu2 O3 and 0.4-1.0wt.% Dy2 O3 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a luminous pigment,
More specifically, the present invention relates to a luminous pigment that retains high luminance for a long time and has excellent water resistance and weather resistance.

[0002]

2. Description of the Related Art Conventionally, phosphorescent pigments include CaS;
i, CaSr; Bi, ZnS; Cu, ZnCdS; Cu
Are known. These sulfide-based luminous pigments lack chemical stability, and the afterglow time that can be visually confirmed is as short as about 30 minutes to 3 hours, and their practical use has been limited. Chemically stable
Luminescent pigments (luminous phosphors) having a long afterglow time that can be confirmed with the naked eye have been proposed (see Japanese Patent No. 2543825). This phosphorescent pigment is a compound represented by MAl ₂ O ₄ , where M is one of calcium, strontium and barium.
The above elements, and europium is added to this compound as an activator, and as a co-activator, at least one of cerium, praseodymium, neodymium, samarium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium Is added. According to the above publication, the chemical stability of the luminous pigment is high because it is an oxide-based pigment, and has high light resistance.The afterglow time is much longer than that of the sulfide-based luminous pigment, and It is described that it has a high luminance afterglow characteristic.

[0003]

However, according to the measurements of the present inventors, the above-mentioned conventional luminous pigment has an afterglow time,
That is, a luminance of 10 mcd / m ² recognizable by the naked eye.
(Elapsed time after 15-minute fluorescent lamp, vertical irradiation from a distance of 20 cm, vertical irradiation for 15 minutes and extinguishing) is about 3 to 4 hours. Although the afterglow time of 3 to 4 hours varies greatly depending on the season, even in the summertime, when the night is short, at 10 to 11:00 pm, this conventional phosphorescent pigment loses the luminance recognizable to the naked eye. Will be. Therefore, in order to maintain luminance that can be recognized by the naked eye throughout the night, at least about eight hours of afterglow time is required. For this reason, the use of this conventional phosphorescent pigment is limited in terms of the afterglow time, similarly to the above-mentioned sulfide phosphorescent pigment. Moreover, since this luminous pigment is water-soluble, there is a limitation that it cannot be applied to outdoor structures.

Accordingly, an object of the present invention is to provide a phosphorescent pigment which has a high initial luminance, maintains luminance recognizable to the naked eye for a long time, is chemically stable, and has water insolubility and light resistance. is there.

[0005]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by adding boron (B) to SrAl ₂ O ₄ ; It has been found that light emission can be performed for a long time, and furthermore, after adding dysprosium (Dy), the afterglow time becomes longer, and the present invention has been completed.

That is, according to the present invention, SrCO ₃ ,
Al ₂ O ₃ , H ₃ BO ₃ , Eu ₂ O ₃ and Dy ₂ O ₃
Obtained by sintering a composition containing as an essential component in the presence of carbon (C) and / or hydrogen (H).
Formula _{Sr (AlB) m O n;} EuDy ( wherein, m is 2,
3,4, and n is 4,5,6,7). The composition of the composition is as follows: SrCO ₃ is 30 to 70% by weight;
20-65% by weight of l ₂ O ₃ , 3-12% by weight of H ₃ BO ₃ , 0.4-1.0% by weight of Eu ₂ O ₃
And Dy ₂ O ₃ is preferably 0.4 to 1.0% by weight.

Further, according to the present invention, SrCO ₃ , Al
A fine powder composition containing ₂ O ₃ , H ₃ BO ₃ , Eu ₂ O ₃ and Dy ₂ O ₃ as essential components is prepared by adding carbon (C) in the presence of 2 to 6% by weight of acetone based on the composition. )and/
Or 1000 to 1500 ° in the presence of hydrogen (H)
A method for producing the luminous pigment, wherein the sintering is performed for 1 to 5 hours at C.

Further, according to the present invention, the phosphorescent pigment after sintering is finely pulverized and mixed again, and subjected to 1000 to 1500 ° C. in the presence of carbon (C) and / or hydrogen (H).
And re-sintering for 1 to 5 hours.

Further, according to the present invention, SrCO_Three ; 30
To 50% by weight, Al_Two O_Three 40-65 weight
%, H _Three BO_Three 8 to 12% by weight, Eu_Two O_Three ;
0.4 to 1.0% by weight and Dy_Two O_Three ; 0.4
A composition consisting of 0.7% by weight of carbon is mixed with carbon (C) and
1000 to 1500 in the presence of hydrogen (H)
Sr (A) obtained by sintering at 1 ° C. for 1 to 5 hours.
IB)_Four O₇ Characterized by being represented by EuDy
A luminous pigment is provided.

Further, according to the present invention, SrCO_Three ; 50
To 70% by weight, Al_Two O_Three 20-45 weight
%, H _Three BO_Three 3-5% by weight, Eu_Two O_Three 0.
6 to 0.9% by weight and Dy_Two O_Three 0.6 to
1.0% by weight of the composition is treated with carbon (C) and / or water
At 1000 to 1500 ° C in the presence of hydrogen (H).
Formula Sr (AlB) obtained by sintering for 5 hours_Two O
_Four A phosphorescent pigment characterized by being represented by EuDy;
Provided.

Further, according to the present invention, SrCO_Three ; 40
To 70% by weight, Al_Two O_Three 20 to 50 weight
%, H _Three BO_Three 4 to 7% by weight, Eu_Two O_Three 0.
5 to 0.9% by weight and Dy_Two O_Three From 0.5 to
0.9% by weight of carbon (C) and / or water
At 1000 to 1500 ° C in the presence of hydrogen (H).
Formula Sr (AlB) obtained by sintering for 5 hours_Three O
₆ A phosphorescent pigment characterized by being represented by EuDy;
Provided.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the invention described in each claim will be described. <Inventions of Claims 1 and 2> The present invention provides a phosphorescent pigment according to the present invention as a basic structure of SrCO ₃ , Al ₂ O ₃ , H ₃
BO ₃ , Eu ₂ O ₃ and Dy ₂ O ₃ are specified. SrCO ₃ (strontium carbonate), Al ₂ O ₃ (aluminum oxide), H ₃ BO ₃ (boric acid), Eu ₂ O ₃ (europium oxide) and Dy ₂ O
₃ (Dysprosium oxide) desirably has as high a purity as possible. Here, a first-grade reagent or more, preferably a special-grade reagent is used. The compounding ratio of these strontium carbonate, aluminum oxide, boric acid, europium oxide and dysprosium oxide is preferably within the above range. S with light time and high initial brightness
It may not be able to obtain a phosphorescent pigment represented by formula of _{EuDy; r (AlB) m O} n.

[0013] The _{Sr (AlB) m O n;} m in phosphorescent pigment represented by Formula of EuDy, the combination of n is different, each emission colors, afterglow time, initial luminance, and other physical properties different to give However, it goes without saying that they are all included in the scope of the present invention.

[0014] The present invention <invention of claim 3, wherein> is the claims 1 and 2 wherein the _{Sr (AlB) m O n;} EuD
This defines a method for producing a phosphorescent pigment represented by the chemical formula of y. In this method, preferably, first,
Boric acid (H ₃ BO ₃ ) is finely powdered. Strontium carbonate (SrCO ₃ ) is sifted through a sieve to separate it into fine powder. Then, mix each chemical in the above mixing ratio and put in a container.
In the presence of acetone and thoroughly stirred in the container with a stirrer. When the mixture is sufficiently stirred, the mixture of the respective chemicals adheres to the wall surface of the container, so that the mixture is taken out of the container, made into a fine powder again, put into the container, and further sufficiently stirred with a stirrer. This operation is repeated several times.

[0015] Then, the mixture of the respective chemicals, which has been sufficiently stirred, is put in a container such as a crucible, and the lid is put. A crucible containing the mixture is put into a crucible large enough to contain the crucible, covered with carbon, and further covered. . Put in the furnace in this state, 100
A temperature in the range 0 to 1500 ° C., preferably 120 ° C.
The sintering is carried out at 0 to 1300 ° C. for a time ranging from 1 to 5 hours, preferably for about 3 hours. At this time, sintering may be performed in the coexistence of carbon and hydrogen, or may be performed in the presence of hydrogen alone. Naturally cooled After sintering is _{complete, Sr (AlB) m O n} ; EuDy (m, n the foregoing as) By taking out the sintered product was the phosphorescent pigment represented by Formula from the crucible, the manufacturing finish.

<Invention of Claim 4> This invention defines a more preferable method for producing the luminous pigment of the present invention. In other words, this production method, once manufactured Sr (AlB) _m O _n the invention of claim 3; presence of the phosphorescent pigment represented by Formula of EuDy, again carbon (C) and / or hydrogen (H) 1000 to 1500 below
Sintering is performed at 1 ° C. for 1 to 5 hours. When resintering is performed in this way, the reason is unknown, but the initial luminance and the afterglow time both increase by about 20 to 30%, and even if the afterglow time approaches the end and the luminance decreases,
The light emission does not darken.

<Invention of Claim 5> This Sr (Al
B) ₄ O ₇ ; a phosphorescent pigment represented by the chemical formula of EuDy
The afterglow time of Sr (AlB) ₂ O ₄ ; E
It is longer than the luminous pigment represented by the chemical formula of uDy, but has low initial luminance and emits blue light. This luminous pigment differs only in the compounding ratio of each chemical, and the other manufacturing methods and changes in properties due to the same are the same as in the above-described invention, and therefore description thereof is omitted.

<Invention of Claim 6> This Sr (Al
B) The phosphorescent pigment represented by the chemical formula of ₂ O ₄ ; EuDy is
Conversely, the afterglow time is Sr (AlB) ₄ O described above.
₇ ; shorter than the luminous pigment represented by the chemical formula of EuDy,
It has a high initial luminance and emits green light. The luminous pigment differs only in the compounding ratio of each chemical, and other manufacturing methods and changes in characteristics due to the same are the same as those of the above-described invention, and therefore description thereof is omitted.

<Invention of Claim 7> This Sr (Al
B) The phosphorescent pigment represented by the chemical formula of ₃ O ₆ ; EuDy
The above-mentioned luminous pigment Sr (AlB) ₄ O which emits blue light
₇ ; Luminescent pigment Sr that emits EuDy and green
(AlB) ₄ O ₇ ; which has good characteristics of EuDy. In other words, this luminous pigment has a long afterglow time and a high initial luminance, does not cause darkening even when the luminance is reduced, and only differs in the compounding ratio of each chemical. Other manufacturing methods and changes in characteristics due to the same are the same as those of the above-described invention, and therefore description thereof is omitted.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. <Example 1> SrCO ₃ to 39 wt%, the Al ₂ O ₃ 5
0% by weight, 10% by weight of H ₃ BO ₃ and 0.1% of Eu ₂ O ₃ .
To a fine powder composition composed of 47% by weight and 0.53% by weight of Dy ₂ O ₃ , 5% by weight of acetone was added to the composition and mixed well, and the mixture was put in a crucible and a lid was placed thereon. Then, the crucible containing the mixture is put into a crucible large enough to contain the crucible, covered with carbon, and covered. In this state, it is placed in a furnace and sintered at a temperature in the range of 1250 ± 20 ° C. for about 3 hours, and then naturally cooled to obtain a luminous pigment Sr (AlB) ₄ O ₇ ; EuDy which emits blue light. Was. The phosphorescent pigment is vertically irradiated with a 15-w fluorescent lamp from a distance of 20 cm for 15 minutes, and immediately after the fluorescent lamp is turned off, the luminance is measured at predetermined time intervals using a luminance meter (Minolta 10, lens diopter: 1 degree). did.

<Embodiment 2> SrCO_Three 57% by weight, A
l_Two O_Three 38% by weight of H_Three BO_Three 3.5% by weight of E
u_Two O_Three 0.7% by weight, Dy_Two O_Three 0.8% by weight
5% by weight of the composition with respect to the composition.
Mix well in the presence of seton and use Example 1
The phosphorescent pigment Sr (A
IB)_Two O _Four EuDy was obtained. Brightness of the obtained phosphorescent pigment
The degree was measured in the same manner as in Example 1.

Example 3 53% by weight of SrCO ₃ , A
l ₂ O ₃ of 41 wt%, the H ₃ BO ₃ 4.5 wt%, E
A mixture in the form of fine powder consisting of 0.6% by weight of u ₂ O ₃ and 0.9% by weight of Dy ₂ O ₃ was added in an amount of 5% by weight based on the composition.
Was sufficiently mixed in the presence of acetone, and a phosphorescent pigment Sr (AlB) ₃ O ₆ ; EuDy, which emits green blue light, was obtained from this mixture in the same manner as in Example 1. The luminance of the obtained phosphorescent pigment was measured in the same manner as in Example 1.

<Comparative Example 1> MAl ₂ O shown in the conventional example
₄ ; The luminance of a representative EuDy (N Nekko Kagaku, N night light) was measured in the same manner as in Example 1.

Comparative Example 2 The luminance of a commercially available luminous pigment (Chemicala, manufactured by Nippon Chemics Co., Ltd.) was measured in the same manner as in Example 1. Table 1 shows the above measurement results.

[0025]

[Table 1]

<Example 4> The phosphorescent pigment which emits blue light obtained in Example 1 was made into a fine powder, again put in a crucible, and a lid was placed. The crucible containing the mixture was placed in a crucible large enough to contain the crucible. Cover with carbon and cover. In this state, it was put into a furnace, sintered at a temperature in the range of 1250 ± 20 ° C. for about 3 hours, and then naturally cooled to obtain a re-sintered product. The luminance of the resintered product was measured in the same manner as in Example 1.

Example 5 The phosphorescent pigment emitting green light obtained in Example 2 was made into a fine powder, and a resintered product was obtained in the same manner as in Example 4. Example 1 Example 1
Was measured in the same manner as described above.

Example 6 The phosphorescent pigment emitting green blue light obtained in Example 3 was made into a fine powder, and a resintered product was obtained in the same manner as in Example 4. The luminance of the resintered product was measured in the same manner as in Example 1. Table 2 shows the above measurement results.

[0029]

[Table 2]

The luminous pigment of the present invention having the above-mentioned excellent properties can be used in the form of application on the surface of various commodities, or by including it in a material such as paper, resin, rubber, glass or metal. Is also good. In addition, when the luminous pigment of the present invention is mixed with printing ink and printed, the printed surface emits light when color-copied, and the copy is different from the original printed matter. Can be. Furthermore, it will be understood that the water-insoluble nature allows for a wide range of applications to structures exposed to the elements, night signs, and the like.

[0031]

As described above in detail, since the luminous pigment provided by the present invention is an oxide, it is chemically more stable than a conventional sulfide-based luminous pigment, and has an afterglow time,
The initial luminance is also excellent. In addition, the present invention can be applied to outdoor structures exposed to wind and rain because of being insoluble in water. According to the invention of claim 4, the luminous pigment once obtained is further subjected to the sintering operation again,
It is possible to obtain a phosphorescent pigment which is more excellent in chemical stability, afterglow time and initial luminance. According to the invention of claims 5 to 7, it is possible to provide a luminous pigment which emits blue, green and green blue and has excellent chemical stability and excellent afterglow time and initial luminance.

Claims (7)

[Claims] 1. SrCO ₃ , Al ₂ O ₃ , H ₃ BO ₃ ,
Formula Sr (AlB) _m O obtained by sintering a composition containing Eu ₂ O ₃ and Dy ₂ O ₃ as essential components in the presence of carbon (C) and / or hydrogen (H).
_n ; EuDy (wherein m is 2, 3, 4 and n is 4,
5, 6 and 7). 2. The composition according to claim 1, wherein the composition comprises 30 SrCO _3.
To 70% by weight, to Al ₂ O ₃ is 20 to 65 wt%, to H ₃ BO ₃ is not 3 12 wt%, Eu ₂ O ₃ is 0.4 to 1.0 wt% and Dy ₂ O ₃ 0.4 The luminous pigment according to claim 1, wherein the amount is from 1.0 to 1.0% by weight. 3. SrCO ₃ , Al ₂ O ₃ , H ₃ BO ₃ ,
A fine powder composition containing Eu ₂ O ₃ and Dy ₂ O ₃ as essential components is prepared by adding carbon (C) and / or hydrogen (H) in the presence of 2 to 6% by weight of acetone based on the composition. 3. The method for producing a luminous pigment according to claim 1, wherein sintering is performed at 1,000 to 1500 [deg.] C. for 1 to 5 hours in the presence. 4. The phosphorescent pigment after sintering is finely pulverized and mixed again, and resintered at 1000 to 1500 ° C. for 1 to 5 hours in the presence of carbon (C) and / or hydrogen (H). 4. The method for producing a luminous pigment according to claim 3, wherein: 5. SrCO ₃ ; 30 to 50% by weight, A
l ₂ O ₃ : 40 to 65% by weight, H ₃ BO ₃ : 8 to 12% by weight, Eu ₂ O ₃ : 0.4 to 1.0% by weight
And Dy ₂ O ₃ ; 0.4 to 0.7% by weight, sintered at 1000 to 1500 ° C. for 1 to 5 hours in the presence of carbon (C) and / or hydrogen (H) The obtained phosphorescent pigment represented by the formula Sr (AlB) ₄ O ₇ ; EuDy. 6. SrCO ₃ ; 50 to 70% by weight, A
l ₂ O ₃ ; 20 to 45% by weight, H ₃ BO ₃ ; 3 to 5% by weight, Eu ₂ O ₃ ; 0.6 to 0.9% by weight and Dy ₂ O ₃ 0.6 to 1.0% by weight The composition of
100 in the presence of carbon (C) and / or hydrogen (H)
A luminous pigment represented by the formula Sr (AlB) ₂ O ₄ ; EuDy, obtained by sintering at 0 to 1500 ° C. for 1 to 5 hours. 7. SrCO ₃ ; 40 to 70% by weight, A
l ₂ O ₃ ; 20 to 50% by weight, H ₃ BO ₃ ; 4 to 7% by weight, Eu ₂ O ₃ ; 0.5 to 0.9% by weight and Dy ₂ O ₃ ; 0.5 to 0.9% by weight % Of the composition in the presence of carbon (C) and / or hydrogen (H)
A phosphorescent pigment represented by the formula Sr (AlB) ₃ O ₆ ; EuDy, obtained by sintering at 000 to 1500 ° C. for 1 to 5 hours.