JPH10319834A - Clay composition containing light accumulating fluorescent body and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the light accumulating fluorescent body clay composition which contains a light accumulating fluorescent body with superior light resistance and afterglow characteristics and also is chemically stable and superior in storage stability, and its production. SOLUTION: The clay composition containing a light accumulating fluorescent body is formed by incorporating the light accumulating fluorescent body based upon a compound, represented as MAl2 O4 (M is at least >=1 kind of metal element selected out of calcium, strontium, and barium) as base crystal in a clay base material consisting principally of starch. The clay composition containing the light accumulating fluorescent body is produced by adding a light accumulating fluorescent body to the clay base material consisting principally of starch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminous phosphor-containing clay composition and a method for producing the same. More specifically,
A light-storing phosphor-containing clay composition containing a light-storing phosphor excellent in afterglow characteristics, having excellent storage stability, and maintaining these properties even after the production of a molded article, and the same. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Flour clay obtained by adding a flour material such as flour to a synthetic resin emulsion such as polyvinyl acetate emulsion, a salting-out astringent, a filler, a swelling lubricant, borax, and other materials and kneading the mixture. Flour clay is widely known as a clay for learning and play, a clay for crafts, etc. because of its high safety, odorlessness, easy availability of materials, and no oil ooze. I have. Flour clay is usually manufactured and sold in the form of colored products by adding coloring agents such as pigments and dyes and pigments, for the original purpose of using it for work and modeling, and as a coloring agent in that case. For foods, food dyes excellent in safety and non-toxic general-purpose dyes and pigments are used.

[0003] For this reason, a work or a shaped article (hereinafter sometimes collectively referred to as a “shaped article, etc.”) produced using such conventional flour clay is used in the daytime or in a bright place with lighting. Can exert its decorative effect and enjoy using it, but in the dark place, it can exert its decorative effect, as well as other general works, crafts, ornaments, etc. And cannot enjoy using it.

[0004] On the other hand, with the diversification of life, attention has been widely paid to the way of night lighting in a room or the like, and the lighting is effectively performed to provide a gorgeous atmosphere or an unprecedented fantasy. Attempts have been made to create a typical atmosphere and other new atmospheres. However, the creation of such an atmosphere has been mainly performed by selecting, designing, and arranging lighting equipment.
Conventionally, there has been almost no attempt to actively create an atmosphere at night or the like by using shaped articles and general ornaments made of clay or the like.

[0005] The present inventors have disclosed a phosphorescent phosphor in flour clay, and a molded article produced therefrom emits fluorescent light at night or in other dark places, resulting in a fantastic atmosphere like never before. We have been developing new clay that can produce gorgeous atmospheres and decorative effects.

Generally, the afterglow time of a phosphor is extremely short,
When the external stimulus is stopped, its light emission is attenuated immediately,
In rare cases, afterglow is observed with the naked eye for a very long time (several tens to several hours) even after stimulation with ultraviolet light or the like or after the stimulation is stopped, and these are usually distinguished from phosphors. Separately, they are called phosphorescent phosphors or phosphors.

The phosphorescent phosphor is CaS: Bi.
(Purple blue light emission), CaSrS: Bi (blue light emission), Zn
Sulfide phosphors such as S: Cu (green emission) and ZnCdS: Cu (yellow to orange emission) are known, and any of these sulfides is chemically unstable or has light resistance. There were many practical problems such as inferiority.

At present, zinc sulfide phosphorescent phosphors (ZnS: Cu) exclusively used in the market, particularly when exposed to moisture, undergo photodecomposition by ultraviolet rays to cause blackening or decrease in luminance. It is difficult to use it in applications that are exposed to sunlight, and its applications, such as luminous clocks, evacuation taxiways, and outdoor nighttime displays, have been limited. Even when this zinc sulfide phosphorescent material is used in a luminous timepiece, the afterglow time for which the time can be recognized by the naked eye is about 30 minutes to about 2 hours. At present, it is necessary to add a radioactive substance and use a self-luminous luminous paint that emits light at all times stimulated by the energy.

On the other hand, there is known a phosphorescent phosphor which has much more persistence than conventional sulfide phosphors, is chemically stable, and has excellent light resistance for a long period of time (Patent No. 2543825).

[0010] Therefore, the above-mentioned phosphorescent phosphor is obtained, and the phosphorescent phosphor is added to flour clay mainly composed of flour, which is most commonly used as flour clay, to obtain flour clay containing phosphorescent phosphor. When manufactured, the shaped articles produced using the flour clay obtained thereby emit light in the dark only from the surface of the shaped article, etc., and emit weak light, a fantastic like never before I couldn't produce a perfect atmosphere or decoration effect.

[0011]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned drawbacks of the clay containing the luminous phosphor, and is chemically stable and has excellent light resistance and storage stability for a long time. It is an object of the present invention to provide a clay composition containing a phosphorescent phosphor having a long-term afterglow characteristic, and a method for producing the same.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a phosphorescent phosphor and a clay base mainly composed of flour, and as a result, have found that a specific phosphorescent phosphor and a specific clay base allow the above described phosphor. It has been found that a luminous phosphor-containing clay composition having desired properties can be obtained. Specifically, the present inventors have found that a starch-based clay substrate has the formula: MA
a phosphorescent phosphor containing a compound represented by l ₂ O ₄ (where M represents at least one metal element selected from calcium, strontium and barium) as a mother crystal;
When the phosphorescent substance preferably has an average particle diameter of 0.1 to 30 μm, and preferably the phosphorescent substance coated with an inorganic material and / or an organic material, the clay is used. Is more effectively suppressed,
It has been found that a clay containing the same does not cause dripping of the dough (decrease in curing) during storage and can maintain hardness suitable for work and modeling for a long period of time.

That is, the present inventors have made a clay base material using starch such as corn starch as a flour material constituting the clay, instead of using flour, which has been widely used in the past, and used the phosphorescent phosphor described above. When a luminous phosphor-containing clay composition is manufactured by containing, a shaped article or the like produced using the same is not only from the surface of the shaped article, but also emits light from the inside, for a long time in a dark place. Having a strong light emission continuously, and even if a long period of time elapses after the production of a molded article, such a strong light emission is maintained without being lost, a fantastic atmosphere like never before and a new decorative effect We found that we could produce such as. Furthermore, the present inventors have found that such a clay composition containing a luminous phosphor does not undergo any deterioration during storage of the clay, and can maintain good physical properties over a long period of time.

In addition, the present inventors have aimed at producing the above-mentioned clay composition containing a phosphorescent phosphor even if the phosphorescent phosphor is mixed with other raw materials in the initial stage of the clay production. Although it is possible to obtain a phosphorescent phosphor-containing clay composition having good light emitting properties, the phosphorescent phosphor is added at a later stage without being added at an initial stage, that is, other than starch and phosphorescent phosphor. Other clay raw materials are mixed and kneaded to prepare a starch-based clay base material in advance, and then a phosphorescent phosphor-containing clay composition is added to the pre-prepared clay base material by adding a phosphorescent phosphor. When manufactured, the resulting phosphorescent phosphor-containing clay composition gradually increases its hardness during storage, and becomes more suitable for use in ordinary work and modeling, and at that time, Phosphorescent phosphor on clay substrate prepared in advance Addition, it found that it is more preferably carried out in the form of a kneaded product of the phosphorescent phosphor and a plasticizer, and have completed the present invention based on their various findings.

Accordingly, the present invention provides a method for preparing a starch-based clay substrate comprising the formula: MAl ₂ O ₄ (where M is calcium,
A phosphorescent phosphor containing a compound represented by at least one metal element selected from strontium and barium) as a mother crystal. .

The present invention includes, as a preferred embodiment, the above-mentioned clay composition containing the phosphorescent phosphor coated with a water-resistant inorganic material and / or an organic material. Further, in the present invention, the above-mentioned starch-based clay base material is prepared using an aqueous gel comprising starch, borax and / or boric acid and polyvinyl alcohol, and other clay raw materials. A clay composition is included as a preferred embodiment.

The present invention relates to a method of preparing a clay base material mainly composed of starch by mixing and kneading raw materials for clay other than starch and a phosphorescent phosphor, and then,
A phosphorescent phosphor whose mother crystal is a compound represented by the formula: MAl ₂ O ₄ (where M represents at least one metal element selected from calcium, strontium and barium) is added and further kneaded. A method for producing a luminous phosphor-containing clay composition, characterized in that:

In the present invention, in the above-mentioned production method, a kneaded product of a luminous phosphor and a plasticizer is prepared in advance, and the kneaded product is added to the previously prepared clay base material to prepare a luminous phosphor. A method for producing the body-containing clay composition is included as a preferred embodiment thereof. Furthermore, the present invention provides a starch base-based clay base material by mixing and kneading starch, borax and / or an aqueous gel comprising boric acid and polyvinyl alcohol, and other clay ingredients other than the phosphorescent phosphor. Then, a method of producing the clay composition containing the phosphorescent phosphor by adding the phosphorescent phosphor to the mixture and further kneading the mixture is included as a preferred embodiment thereof.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the contents of the present invention will be described in detail. The phosphorescent phosphor used in the present invention is MAl ₂ O
₄ (where M represents at least one metal element selected from calcium, strontium and barium)
The compound represented by is used as a mother crystal. This phosphorescent phosphor is safe for the human body because it does not contain a radioactive substance, and has excellent light resistance and excellent afterglow characteristics. Specific examples include CaAl ₂ O ₄ , S
rAl ₂ O ₄ , St _x Ca _1-x Al ₂ O ₄ , Sr _r Ba _1-r Al
₂ O _{4 and the} like. The average particle size of the phosphorescent phosphor is preferably 0.1 to 30 μm, and 0.5 to 30 μm.
It is more preferable that the thickness be 20 μm. When the average particle size of the phosphorescent phosphor is less than 0.1 μm, it becomes difficult to store the irradiated energy, so that the afterglow characteristic tends to be low,
On the other hand, if the thickness exceeds 30 μm, the surface of the produced shaped article becomes rough and the appearance is poor, and the phosphorescent phosphor may fall off the surface, which is not preferable.

In the phosphorescent phosphor represented by MAl ₂ O ₄ , M is a compound comprising a plurality of metal elements obtained by adding magnesium to at least one metal element selected from calcium, strontium and barium. A phosphorescent phosphor formed as a crystal can also be used.

Further, europium (E) is used as an activator.
u) is added to the metal element represented by M in an amount of 0.001 to 10 mol%, and lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, terbium is used as a co-activator in addition to a phosphorescent phosphor and an activator. A phosphorescent phosphor to which at least one element selected from dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin, and bismuth is added in an amount of 0.001 to 10 mol% can be used.

The content of the phosphorescent phosphor is preferably from 3 to 30% by weight, more preferably from 5 to 15% by weight, based on the total weight of the clay composition containing the phosphorescent phosphor. When the content of the phosphorescent phosphor is less than 3% by weight, the afterglow properties of the produced shaped article and the like are insufficient. On the other hand, when the content exceeds 30% by weight, the hardness of the clay composition increases, and the production of clay is increased. It is not preferable from the viewpoint of the cost and the like because the ease of performing the operation and the forming are reduced.

The luminous phosphor-containing clay composition of the present invention comprises:
A type of flour clay in which the flour constituting the clay is mainly made of starch. In the luminous phosphor-containing clay composition of the present invention, the proportion of starch is preferably from 70 to 100% by weight, more preferably from 80 to 100% by weight, based on the total weight of the flour used as the clay base material. .
When the proportion of starch in the total weight of flour used for the clay base material is less than 70% by weight (when the content of other flours such as flour exceeds 30% by weight), a shaped article obtained using clay Since the light transmittance of the molded article or the like is reduced, the light emission from the inside of the shaped article or the like is apt to be weakened, and the effect of adding the phosphorescent phosphor is not sufficiently exhibited. It is preferable that the starch content is about 20 to 70% by weight based on the total weight of the luminous phosphor-containing clay composition from the viewpoint of easiness of production of clay, easiness of work and molding, cost, and the like. .

Examples of the starch used in the clay composition containing a phosphorescent phosphor of the present invention include corn starch, potato starch, wheat starch, rice starch, tapioca starch, potato starch, mylo starch, gelatinized starch of the above-mentioned starch, and modified starch. Starch and the like can be mentioned. In the present invention, one of the above-mentioned starches may be used alone, or two or more may be used in combination. Among them, in the luminous phosphor-containing clay composition of the present invention, the use of one or more of corn starch, potato starch and tapioca starch as the starch is advantageous in terms of cost, whiteness, and low stickiness. Is preferred.

The clay composition containing a luminous phosphor of the present invention may contain, together with the above-mentioned starch, a small amount (less than 30% by weight based on the total weight of the flour usually used for clay) of a flour other than starch, such as wheat flour. Corn flour, rice flour, buckwheat flour,
One or more kinds of processed flour (eg, bread, bread crumbs, etc.) may be contained. When flour other than starch, such as wheat flour, is used in combination, use of pregelatinized flour is preferred in terms of safety because the amount of the thickener added by chemical synthesis can be reduced.

In the clay composition containing a phosphorescent phosphor of the present invention, the phosphorescent phosphor described above may be used directly as it is, or the phosphorescent phosphor having been subjected to a surface treatment may be used. Also in this case, it is possible to obtain a luminous phosphor-containing clay composition capable of producing a shaped article or the like that emits light strongly in a dark place. Among them, in the present invention, it is preferable to use a phosphorescent phosphor coated with a water-resistant inorganic material and / or an organic material. When the above-mentioned phosphorescent phosphor coated with a water-resistant inorganic material and / or organic material is used, in the phosphorescent phosphor-containing clay composition obtained thereby, the dough (hardness) of the dough during storage and the like is used. ), The hardness suitable for work and modeling can be maintained for a long period of time, and the deterioration of the clay composition containing the luminous phosphor is more unlikely to occur. The molded article to be manufactured can maintain its emission characteristics favorably over a long period of time.

As the water-resistant inorganic and organic materials used for coating the luminous phosphor, the luminous phosphor coated with the water-resistant material does not impair or reduce the luminous characteristics of the luminous phosphor. Any material may be used as long as it is a water-resistant material that does not degrade the quality of the clay to which is added.

In the present invention, together with the starch and the phosphorescent phosphor described above, various clay raw materials conventionally used in flour clay can be used. Examples of clay raw materials that can be used in the present invention include, but are not limited to, adhesives (eg, synthetic resin powders such as polyvinyl acetate and aqueous emulsions thereof), salting-out astringents (eg, borax, aluminum sulfate). , Potassium sulfate, sodium sulfate, etc.), thickeners (eg, polyvinyl alcohol, sodium cellulose glycolate, etc.), aqueous gels composed of borax and / or boric acid and polyvinyl alcohol, surfactants (eg, sucrose fatty acid esters, glycerin fatty acids) Esters, various surfactants such as sorbitan fatty acid esters), antioxidants (eg, dextrin, starch syrup, etc.),
pH adjusters (eg, organic acids such as tartaric acid), preservatives (eg, sorbic acid, potassium sorbate, sodium dehydroacetate, benzoic acid, etc.), oils (eg, shortening, etc.), hardening inhibitors (eg, salt, etc.), plastics Agents (eg, propylene glycol), liquid paraffin, antioxidants, coloring agents such as pigments and dyes and pigments, and fragrances. The kind of the raw material used in the phosphorescent phosphor-containing clay composition of the present invention and the amount of the raw material may be appropriately determined according to the use of the phosphorescent phosphor-containing clay composition, the hardness required for the composition, and the like.

The method for producing the luminous phosphor-containing clay composition of the present invention is not particularly limited, and it can be produced according to a method generally used in the production of flour clay, for example, (1) starch, A method for producing a clay composition containing a phosphorescent phosphor by adding and mixing a raw material other than the phosphorescent phosphor and water and kneading to prepare a clay base material in advance, and then adding and kneading the phosphorescent phosphor thereto. (2) a method of mixing a phosphorescent phosphor with starch, other raw materials and water in an early stage of production, kneading and directly producing a clay composition containing a phosphorescent phosphor, (3) a phosphorescent phosphor May be added at an intermediate stage of preparing the clay, and the mixture may be kneaded to produce a phosphorescent phosphor-containing clay composition.

[0030] Of the above methods, the method (1) is preferably employed as a method for producing the clay composition containing a luminous phosphor of the present invention. After storage, the luminous phosphor-containing clay composition produced by the method (1) gradually increases in hardness while being stored for an appropriate period (usually about 1 week to 6 months). , And has a hardness suitable for use in ordinary work and modeling. On the other hand, the luminous phosphor-containing clay composition obtained by the method (2), in which the luminous phosphor is added at an early stage during the production of the clay, does not significantly change its hardness when stored after production. In many cases, generally, since a soft state immediately after production or a state of a degree slightly harder than that is maintained, it is preferable to use a soft phosphorescent phosphor-containing clay composition when performing a working operation or a molding operation, The phosphorescent phosphor-containing clay composition obtained by the method (2) may be used.

In producing the luminous phosphor-containing clay composition by employing the above method (1),
The phosphorescent phosphor may be directly added to the previously prepared clay base material in the form of a powder, but the phosphorescent phosphor is prevented from scattering at the time of addition, and the phosphorescent phosphor is dispersed into the clay base material. From the viewpoint of uniform mixing of the phosphorescent phosphor, a liquid plasticizer is added to the phosphorescent phosphor to prepare a paste-like kneaded product of the phosphorescent phosphor and the plasticizer, and the kneaded material is prepared in advance. It is preferable to adopt a method of adding to the clay base material. In this case, the amount of the plasticizer to be used with respect to the phosphorescent phosphor is generally preferably a weight ratio of phosphorescent phosphor: plasticizer = 95: 5 to 5:95. As the plasticizer, propylene glycol or the like is preferably used. Also, when a phosphorescent phosphor or a kneaded mixture of a phosphorescent phosphor and a plasticizer is added to a previously prepared clay base material, the clay becomes hard due to a shortage of water due to the mixture of the phosphorescent phosphor. Since there are many, the additional water is added at the time of adding the kneaded material of the phosphorescent phosphor or the phosphorescent phosphor and the plasticizer, so that the phosphorescent phosphor-containing clay composition having the desired hardness can be obtained. It is good to

The kneading method and kneading apparatus for producing the phosphorescent phosphor-containing clay composition are not particularly limited, and the kneading method and kneading apparatus conventionally used for producing flour clay may be employed. it can. Further, the production temperature of the phosphorescent phosphor-containing clay composition and the like are not particularly limited,
Generally, it is preferable to manufacture at a temperature of 5 to 60 ° C. from the viewpoint of easy kneading and prevention of quality deterioration.

The hardness of the clay composition containing a luminous phosphor of the present invention can be adjusted according to the application and the like. For example, the clay used by repeated molding is preferably soft and dried after molding. Clay is preferably hard to hard. The luminous phosphor-containing clay composition of the present invention may be stored, preserved, distributed, and sold by packaging it using a plastic film or other hermetically sealed packaging material or packaging container that is impermeable to moisture or moisture.

When a molded article such as an artificial flower, a doll, other decorative articles or a workpiece is produced using the luminous phosphor-containing clay composition of the present invention, the molded article obtained by the method is as follows: It emits light for a long time in a dark place, and can produce a fantastic atmosphere, a gorgeous atmosphere, and a new atmosphere like never before. Furthermore, a molded article produced using the luminous phosphor-containing clay composition of the present invention emits strong light in a dark place, and thus can be effectively used as various marks (markers) in a dark place. .

[0035]

EXAMPLES The present invention will be described below in more detail with reference to examples and the like, but the present invention is not limited thereto.
In the following examples, “parts” and “%” indicate “parts by weight” and “% by weight” unless otherwise specified. Further, in the following examples, the hardness of the clay (a luminous phosphor-containing clay composition), and the light emitting state and the afterglow luminance of the luminous phosphor-containing clay composition (a molded article) were determined as follows. . In addition, the feel and the formability of the clay were evaluated according to the evaluation criteria shown in Table 3 below.

[Method of judging the hardness of clay] After thoroughly washing the hands and wiping off the moisture, the clay is kneaded at room temperature, and the degree of hardness of the clay is determined according to the criteria shown in Table 1 below. Judged.

[0037]

[Table 1] Criteria for determining hardness of clay 5 points: Hard, with waist. 4 points: somewhat hard. 3 points: Normal. 2 points: somewhat soft. 1 point: very soft.

[Judgment Method of Light Emitting State and Afterglow Luminance of Phosphorescent Phosphor-Containing Clay Composition] A dried thin circular plate-shaped molded article (test piece) produced using the phosphorescent phosphor-containing clay composition.
(Diameter × thickness = 25 mm × 3 mm) was irradiated with light for 10 minutes at a distance of 20 cm from a black light (“FL10BL-B” manufactured by National; 10 watts), and then visually observed in a dark place by the following method. According to the criterion shown in Table 2, the light emission state immediately after the light irradiation and the afterglow luminance immediately after the light irradiation and after 6 hours from the light irradiation were determined.

[0039]

[Table 2] Criteria for luminous state and afterglow luminance of clay composition containing luminous phosphor 発 光Emission state : 5 points: Transparent luminescence, no dullness, and excellent luminescence. 4 points: There is a sense of transparency in light emission, there is no dullness, and there is good light emission. 3 points: Low transparency of light emission, slight dullness, but almost good light emission. 2 points: Transparency of light emission is extremely low, there is dullness, and light emission is slightly inferior. 1 point: Light is emitted only from the surface, is dull, and has poor light emission. ○ Afterglow luminance : 5 points: The afterglow luminance is extremely strong, and light is emitted clearly. 4 points: The afterglow luminance is strong and light is emitted almost clearly. 3 points: Slightly inferior in afterglow luminance and slightly lacking in sharpness. 2 points: The afterglow luminance is very weak, and light emission is slightly observed. 1 point: The afterglow luminance is extremely weak, and almost no light emission is observed.

[0040]

[Table 3] Criteria for evaluation of texture and formability of clay A: Good touch, smooth, firm and firm, suitable for normal molding. B: The feel is almost good, and it is smooth and slightly hard, and is suitable for ordinary molding. C: The feel is almost good, it is almost smooth, and it is slightly soft, but it can be used for ordinary modeling. D: Although it is very soft, it does not adhere to hands and can be molded.

Example 1 (1) After mixing 52 parts of propylene glycol, 5 parts of a sorbitan fatty acid ester and 3 parts of an antifungal agent (“Bioside 810” manufactured by Taito Corporation), a polyvinyl acetate aqueous solution (polyvinyl acetate) was mixed. 350 parts and water 36
Were added and kneaded at 25 ° C. for 5 minutes. (2) Next, 500 parts of corn starch, 20 parts of gelatinized flour and 6 parts of polyvinyl alcohol (PVA) (polymerization degree 500) were added to the kneaded product of (1), and kneaded at 25 ° C. for 5 minutes. (3) The kneaded product of (2) is mixed with a borax gel (an aqueous solution obtained by dissolving 90 parts of borax in hot water at a temperature of 75 ° C. in a PVA aqueous solution consisting of 300 parts of PVA and 900 parts of water) while maintaining the product temperature at 60 ° C. 2) with 28 parts
The clay substrate was prepared by kneading for 0 minutes.

(4) Luminescent phosphor coated with a water-resistant material (“N Nightlight G-300MP” manufactured by Nemoto Special Chemical Co., Ltd.)
S-1 ") 10 parts of a plasticizer (propylene glycol) was added to 100 parts and kneaded at 25 ° C to prepare a kneaded product. (5) A kneaded material 1 containing the phosphorescent phosphor obtained in (4) above with respect to 1000 parts of the clay obtained in (3) above.
10 parts were added and kneaded at 40 ° C. for 20 minutes to produce a luminous phosphor-containing clay composition.

(6) The luminous phosphor-containing clay composition obtained in the above (5) is filled in a sealed bag made of polyvinylidene chloride, stored at room temperature (25 ° C.) for one month, and then taken out of the bag. After kneading it and extending it to a thickness of 3 mm with a roller, it was formed with a punch having a diameter of 25 mm, and the diameter x thickness = 25
A shaped product in the shape of a circular thin plate of mm × 3 mm was produced. The above-mentioned circular thin plate-shaped molded product was left at room temperature (25 ° C.) for 1 day and dried to obtain a test piece. (7) The dried circular thin plate-shaped test piece obtained in the above (6) is irradiated with light using a black light as described above, and then brought into a dark place, and is subjected to the above table. 2
According to the criterion shown in the above, the light emission state immediately after light irradiation, and the afterglow luminance immediately after light irradiation and when 6 hours had elapsed after light irradiation were visually determined, as shown in Table 4 below. there were.

Comparative Example 1 (1) Flour 50 instead of 500 parts of corn starch
A luminous phosphor-containing clay composition was produced in exactly the same manner as in Example 1 except that 0 part was used. (2) The clay composition containing a luminous phosphor obtained in the above (1) was filled in a sealed bag made of polyvinylidene chloride, stored at room temperature (25 ° C.) for one month, and then taken out of the bag. In the same manner as described above, a circular thin plate-shaped test piece was produced. (3) Light was irradiated to the dried circular thin plate-shaped test piece obtained in the above (2) in the same manner as in Example 1 to determine the light emission state and the afterglow luminance. The results were as shown in Table 4 below.

[0045]

[Table 4] Example 1 Comparative Example 1 ○ Types of clay base materials Starch clay Flour clay ○ Luminescent state of test piece 51 ○ Afterglow luminance of test piece Immediately after light irradiation 5 26 hours later 31

From the results shown in Table 4 above, the test piece obtained from Example 1 in which a phosphorescent phosphor is contained in a clay base mainly composed of starch has a luminous transparency and has no dullness at all. It can be seen that it has excellent fluorescent properties and has high afterglow luminance not only immediately after light irradiation but also after 6 hours from light irradiation. On the other hand, in the test piece obtained from Comparative Example 1 in which the phosphorescent phosphor is contained in the flour clay base mainly composed of flour, the light emission is large only from the surface, and the light emission is inferior. In addition, it can be seen that afterglow luminance is low immediately after light irradiation, and after 6 hours, light emission substantially disappears and light is no longer emitted.

Example 2 (1) Luminescent phosphor not coated with a water-resistant material as a phosphorescent phosphor (“N Nightlight G” manufactured by Nemoto Special Chemical Co., Ltd.)
-300M "), except that (1) to (1) of Example 1 were used.
A luminous phosphor-containing clay composition was produced in exactly the same manner as in (5). (2) The luminous phosphor-containing clay composition obtained in the above (1) is filled in an airtight bag made of polyvinylidene chloride, packaged and stored, and the luminous property is stored at predetermined intervals shown in Table 5 below. When the phosphor-containing clay composition was taken out of the bag and its hardness was determined according to the criteria shown in Table 1 above,
The results are shown in Table 5 below. In addition, when the hardness of the phosphorescent phosphor-containing clay composition was determined, the feel and the formability of the clay taken out of the bag were evaluated according to the evaluation criteria shown in Table 3 above, and the results are shown in Table 5 below. It was as follows.

(3) Apart from the above (2), the above (1)
Is filled in a sealed bag made of polyvinylidene chloride, which is stored at room temperature (25 ° C.) for one month, taken out of the bag, kneaded, and thickened with a roller. After being extended to 3 mm, it is molded with a die having a diameter of 25 mm to form a circular thin plate-shaped product having a diameter × thickness = 25 mm × 3 mm, which is allowed to stand at room temperature (25 ° C.) for one day and dried. A test piece was used. (4) The dried circular thin plate-shaped test piece obtained in the above (3) was irradiated with light in the same manner as in Example 1, and immediately after the light irradiation and 6 hours after the light irradiation. The afterglow luminance at this time was visually determined according to the criterion shown in Table 2 above, and was as shown in Table 5 below.

Example 3 (1) 110 parts of a kneaded material composed of a luminous phosphor and a plasticizer coated with the same water-resistant material as prepared in (4) of Example 1 was added. A phosphorescent phosphor-containing clay composition was produced in the same manner as in Example 1 using the same formulation as in Example 1 except that the process was performed in the step (1) of Example 1. (2) The luminous phosphor-containing clay composition obtained in the above (1) is filled in an airtight bag made of polyvinylidene chloride, packaged and stored, and the luminous property is stored at predetermined intervals shown in Table 5 below. When the phosphor-containing clay composition was taken out of the bag and its hardness was determined according to the criteria shown in Table 1 above,
The results are shown in Table 5 below. In addition, when the hardness of the phosphorescent phosphor-containing clay composition was determined, the feel and the formability of the clay taken out of the bag were evaluated according to the evaluation criteria shown in Table 3 above, and the results are shown in Table 5 below. It was as follows.

(3) Apart from the above (2), the above (1)
Is filled in a sealed bag made of polyvinylidene chloride, which is stored at room temperature (25 ° C.) for one month, taken out of the bag, kneaded, and thickened with a roller. After being extended to 3 mm, it is molded with a die having a diameter of 25 mm to form a circular thin plate-shaped product having a diameter × thickness = 25 mm × 3 mm, which is allowed to stand at room temperature (25 ° C.) for one day and dried. A test piece was used. (4) The circular thin plate-shaped test piece obtained in (3) was irradiated with light in the same manner as in Example 1,
The afterglow luminance immediately after the light irradiation and at the lapse of 6 hours after the light irradiation was visually determined according to the criterion shown in Table 2 above, and was as shown in Table 5 below.

Also for the phosphor composition containing the phosphorescent phosphor obtained in Example 1 described above, the determination of hardness and evaluation of tactile sensation and formability were performed in the same manner as in Examples 2 and 3. The results were as shown in Table 5 below. Table 5 below shows the determination results of the afterglow luminance immediately after light irradiation and after 6 hours from the dried circular thin plate-shaped test pieces obtained from the luminous phosphor-containing clay composition of Example 1. (Table 1
(Results described in (1)).

[0052]

[Table 5] Example 1 Example 2 Example 3 ○ Kind of phosphorescent phosphor ¹⁾ ○ Timing of addition of phosphorescent phosphor After preparation of clay base material First stage after preparation of clay base material ○ Hardness of clay composition ²⁾ Immediately after production 1 1 1 1 week later 2 2 1 1 month 3 3 2 3 months 3 4 2 6 months 4 5 2 ○ Tactile sensation and shaping of clay composition ²⁾ 1 week CCD 1 month BBC 3 months BBC 6 months B AC ○ Afterglow luminance of test piece Immediately after light irradiation 5.56 6 hours later 3 3 3 1) Kind of phosphorescent phosphor:: "N Nightlight G-300M PS-1" manufactured by Nemoto Special Chemical Co., Ltd. (Luminescent phosphor coated with water-resistant material): "N Nightlight G-produced by Nemoto Special Chemical Co., Ltd." 300M) (Phosphorescent phosphor not coated with water-resistant material) 2) Clay composition containing phosphorescent phosphor

From the results shown in Table 5 above, in the case of the phosphorescent phosphor-containing clay compositions of Examples 1 to 3, the shaped articles obtained therefrom emit strong light, and the light emission lasts for a long time. It can be seen that the time of addition of the phosphorescent phosphor does not significantly affect the light emission. Also, from the results in Table 5 above, when the phosphorescent phosphor was added after the clay base material was prepared in advance using a material other than the phosphorescent phosphor, the phosphorescent phosphor-containing clay composition increased with the elapse of the storage time. It can be seen that the hardness of the object gradually increases and becomes a hardness suitable for ordinary shaping. Furthermore, from the results in Table 5 above, when the phosphorescent phosphor coated with the water-resistant material is used as the phosphorescent phosphor, the hardness of the clay composition containing the phosphorescent phosphor decreases even after storage. It can be seen that it can be more effectively prevented.

Example 4 (1) The phosphorescent phosphor-containing clay was changed by changing the phosphorescent phosphor content in the total weight of the phosphorescent phosphor-containing clay composition to the amounts shown in Table 6 below. Except for producing the composition, each of the clay compositions was produced in exactly the same manner as in Example 1. (2) Each of the luminous phosphor-containing clay compositions obtained in the above (1) was filled in a polyvinylidene chloride sealed bag, stored at room temperature (25 ° C.) for one month, taken out of the bag, and carried out. In the same manner as in Example 1, a circular thin plate-shaped test piece was prepared. (3) The circular thin plate-shaped test piece obtained in the above (2) was irradiated with light in the same manner as in Example 1, and the determination of the afterglow luminance was made according to the criteria shown in Table 2 above. The results were as shown in Table 6 below.

[0055]

[Table 6] Luminescent phosphor content (%) 2 3 5 7 15 20 30 40 ○ Afterglow luminance of test piece Immediately after light irradiation 2 3 4 5 5 5 5 5 6 hours later 1 2 3 3 3 3 4 4

From the results shown in Table 6, it can be seen that if the content of the phosphorescent phosphor is less than 3% of the total weight of the clay composition containing the phosphor, no strong light emission can be obtained.

Example 5 (1) The luminous properties were changed by changing the content of starch (corn starch) in the total weight of the flour used in the luminous phosphor-containing clay composition to the amounts shown in Table 7 below. Except for producing the phosphor-containing clay composition, each of the clay compositions was produced in exactly the same manner as in Example 1. (2) Each of the luminous phosphor-containing clay compositions obtained in the above (1) was filled in a polyvinylidene chloride sealed bag, stored at room temperature (25 ° C.) for one month, taken out of the bag, and carried out. In the same manner as in Example 1, a circular thin plate-shaped test piece was prepared. (3) The circular thin plate-shaped test piece obtained in the above (2) was irradiated with light in the same manner as in Example 1 to determine the light emission state and the afterglow luminance in the above table. The results of visual inspection according to the criteria shown in Table 2 were as shown in Table 7 below.

[0058]

[Table 7] Starch content ratio (%) 60 70 80 100 ○ Luminescent state of test piece 2 3 4 4 ○ Afterglow luminance of test piece Immediately after light irradiation 3 4 5 5 6 hours later 3 3 3 3

From the results shown in Table 7 above, if the starch content is 70% or more, more preferably 80% or more, based on the total weight of the flour used in the luminous phosphor-containing clay composition, light irradiation It can be seen that there is light emission with a transparent feeling, there is no dullness, and there is excellent light emitting property, and that it has high afterglow luminance not only immediately after light irradiation but also after 6 hours from light irradiation.

[0060]

The luminous phosphor-containing clay composition of the present invention has a transparent luminescence upon irradiation with light, has a long afterglow characteristic, and is chemically stable for a long time. Has light resistance. Further, the luminous phosphor-containing clay composition of the present invention does not deteriorate during storage or the like, and can maintain good physical properties over a long period of time. By using the luminous phosphor-containing clay composition of the present invention, a molding capable of producing a fantastic atmosphere, a gorgeous atmosphere, and a new decorative effect, as never before, by utilizing the above-described excellent properties. Goods can be produced, and it can be effectively used as a mark or sign in a dark place. In the case where the phosphorescent phosphor coated with an inorganic material and / or an organic material is used as the phosphorescent phosphor in the clay composition containing a phosphorescent phosphor of the present invention, dripping of the dough (decrease in hardness) occurs during storage of the clay. It does not occur, and it is possible to maintain a hardness suitable for work and modeling for a long period of time, and to further effectively suppress the deterioration of clay. And in producing the phosphorescent phosphor-containing clay composition of the present invention, a starch and a clay material other than the phosphorescent phosphor are mixed and kneaded to prepare a starch-based clay base material in advance, and then When a method of producing a phosphorescent phosphor-containing clay composition by adding a phosphorescent phosphor to the previously prepared clay base material is employed, the hardness of the clay composition is gradually increased at the time of storage to increase the degree of ordinary work and molding. A phosphorescent phosphor-containing clay composition having a hardness suitable for use in the above can be obtained.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Keiji Kato 5-23-37 Higashioi, Shinagawa-ku, Tokyo Mitsubishi Pencil Co., Ltd. Product Development Department (72) Inventor Tadashi Ishimura 16th Nihonbashi Koamicho, Chuo-ku, Tokyo No. 2 Inside Shinwa Service Co., Ltd.

Claims (9)

[Claims] 1. A starch-based clay substrate comprising the formula:
A phosphorescent phosphor containing a compound represented by Al ₂ O ₄ (wherein M represents at least one metal element selected from calcium, strontium and barium) as a mother crystal. Phosphorescent clay-containing clay composition. 2. The phosphorescent phosphor has an average particle diameter of 0.1.
The phosphorescent phosphor-containing clay composition according to claim 1, which has a thickness of from 30 to 30 µm. 3. The luminous phosphor-containing clay composition according to claim 1, wherein the luminous phosphor is coated with a water-resistant inorganic material and / or an organic material. 4. The starch-based clay base material is prepared using starch, an aqueous gel comprising borax and / or boric acid and polyvinyl alcohol, and other clay raw materials. 4. The luminous phosphor-containing clay composition according to any one of claims 1 to 3. 5. The phosphorescent substance according to claim 1, wherein the content of the phosphorescent phosphor is 3 to 30% by weight based on the total weight of the clay composition containing the phosphorescent phosphor. Phosphor-containing clay composition. 6. A raw material for clay other than starch and a phosphorescent phosphor is mixed and kneaded to prepare a starch base-based clay base material in advance, and then the formula: MAl ₂ O ₄ (Wherein M represents at least one or more metal elements selected from calcium, strontium and barium). A phosphorescent phosphor having a compound represented by the formula (1) as a mother crystal is further added and kneaded. A method for producing a luminescent phosphor-containing clay composition. 7. A clay base material containing starch as a main component is prepared by mixing and kneading starch, an aqueous gel comprising borax and / or boric acid and polyvinyl alcohol, and raw materials for clay other than the phosphorescent phosphor. 7. The method for producing a luminous phosphor-containing clay composition according to claim 6, wherein the luminous phosphor is added to the clay base material and kneaded. 8. The phosphorescent fluorescent substance according to claim 6, wherein a kneaded product of a phosphorescent phosphor and a plasticizer is prepared in advance, and the kneaded substance is added to a previously prepared clay base material. A method for producing a body-containing clay composition. 9. The luminous phosphor-containing clay composition according to claim 6, wherein the luminous phosphor is coated with a water-resistant inorganic material and / or an organic material. Method of manufacturing a product.