JP2000034414A - Semi-transmitting phosphorescent resin and its molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high transmittant, luminous resin showing high afterglow by mixing specified amounts of phosphorescent pigments having different particle diameters with a resin. SOLUTION: This resin is prepared by mixing or incorporating 1-4 wt.% resin 1 with a phosphorescent pigment 2 (e.g. SrAl2O4: Eu, Dy) having a particle diameter of 20 μm or above and at least 1 wt.% phosphorescent pigment 2 having a particle diameter of below 20 μm. The total content of the phosphorescent pigments should be 1-4 wt.%. The resin 1 is exemplified by a transmitting resin such as a polycarbonate, an acrylic resin, a polypropylene, an AS resin, a vinyl chloride resin, a polystyrene, a urethane resin, or a polyethylene. As a result, the resin can give a molding which still retains phosphorescence and can permit the one to perceive the side beyond the visually recognized side. Further, the molding has improved decorativeness because it looks as if it emits light from dots in dark after being irradiated with light from a fluorescent lamp or with sunlight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin containing a luminous pigment and a molded article thereof.

[0002]

2. Description of the Related Art Conventionally, the particle size of a phosphorescent pigment mixed or contained in a resin molded article containing a phosphorescent pigment is from several μm to several tens of μm or several hundred μm when it is large. And the average particle size was 10 to 20 μm.

[0003]

However, from the conventional fine to coarse ones, the average particle size is one.
In a resin molded product containing or containing a luminous pigment of 0 to 20 μm, the luminous pigment is finely and densely dispersed in the resin, so that if the content of the luminous pigment in the resin exceeds several percent, light transmission will occur. However, there is a problem that the side opposite to the viewing direction surface of the resin molded product is difficult to see. As a specific example, FIG. 2 shows a conventional resin molded product containing a luminous pigment as viewed from above. SrAl2O4: Eu, Dy occupying 70% of particles having a particle diameter of less than 20 μm is used as a luminous pigment, and colorless polycarbonate is used as a resin. These luminous pigments and polycarbonate were mixed at a ratio of 3:97, and formed into a plate having a thickness of 3 mm. Several μm
Since a large amount of luminous pigments with a fine particle diameter of from 20 μm are contained, the luminous pigments are densely dispersed in the resin, the light transmittance is poor, and the background opposite to the viewing direction of the resin molded product is good. can not see. In addition, it appears that the entire resin molded product emits light in the dark after irradiation with a fluorescent lamp or sunlight.

[0004]

In order to solve these problems, the present invention reduces the content of the luminous pigment in the resin having a particle diameter of less than 20 μm to 1% or less by weight,
The above-mentioned particle size makes the content of the luminous pigment in the resin 1% to 4% by weight, and the total amount of the luminous pigment 1% to 4% by weight. As a result, the particle size becomes 20μ.
m and the overall particle size of the luminous pigment is coarse, the dispersion of the luminous pigment in the resin is sparse, and the light transmittance is improved as compared to those having a large fine particle diameter. . Further, since the afterglow brightness increases as the particle size of the luminous pigment increases, the afterglow luminance of the resin containing the luminous pigment also increases. Therefore, it is possible to recognize the opposite side of the surface of the resin molded product in the viewing direction while maintaining the luminous property. In addition, the resin molded article appears to emit light at a point in the dark after being irradiated with a fluorescent lamp or sunlight, and the decorativeness is improved.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments. (Example 1) FIG. 1 shows a top view of a resin molded product containing a luminous pigment of the present invention. 20 μm as a luminous pigment
SrAl2 occupying 95% of a particle size of not less than 200 μm and not more than 200 μm.
O4: Eu, Dy was used, and colorless polycarbonate was used as the resin. The luminous pigment and the polycarbonate were mixed at a weight ratio of 3:97, and the thickness was 3 mm.
Into a plate shape. Since there are few fine phosphorescent pigments having a size of less than 20 μm, the dispersion of the phosphorescent pigment in the molded article is sparse, the light transmittance is high, and the background opposite to the viewing direction surface can be seen. In addition, since coarse luminous pigments are scattered in the resin molded product, the resin molded product appears to emit dots in the dark after being irradiated with a fluorescent lamp or sunlight. (Example 2) Table 1 shows a list of luminance and light transmittance of a resin molded product containing a luminous pigment. As a resin molded product, a plate having a thickness of 2 mm in which the ratio of the luminous pigment to the colorless polycarbonate was mixed at a weight ratio of 3:97 was produced. Luminescent pigments have a coarse particle size of 20 μm or more in 33%, 50%, 66%
% And 100%. The afterglow luminance is 33% by the ratio of the particle size of 20 μm or more to the luminous pigment.
Is 100, the higher the ratio, the higher the ratio. This is because the larger the particle size of the luminous pigment, the higher the afterglow luminance of the luminous pigment itself. From the viewpoint of light transmission, the ratio of the particle diameter of 20 μm or more to the luminous pigment is 3%.
At 3%, the background on the opposite side of the resin molded article is hardly visible, but at 50% it is slightly visible and at 66% it looks quite good. In addition, as the ratio of the particle diameter of 20 μm or more in the luminous pigment is higher, the luminous pigment seems to emit light in a point. As described above, 2 of the phosphorescent pigments
When the ratio of the particle size of 0 μm or more is 50% or more, the afterglow luminance is increased and the light transmittance is improved.

[0006]

【table 1】

×: The background on the opposite side is hardly visible from the viewing direction surface of the plate. ○: The background on the opposite side is slightly visible from the viewing direction surface of the plate. ◎: The background on the opposite side is clearly visible from the viewing direction surface of the plate. Example 3) Table 2 shows a list of afterglow luminance and light transmittance of a resin molded article containing a luminous pigment having a coarse particle diameter. The particle size of the luminous pigment is 20 μm or more and 200 μm or less, and the ratio of the luminous pigment to the resin molded article containing the luminous pigment is 0.5% by weight.
%, 1%, 2%, 3%, 4%, and 5% to prepare a resin molded plate having a thickness of 2 mm. SrAl2O as luminous pigment
4: Polycarbonate was used with Eu and Dy as resins. The afterglow luminance increases as the ratio of the luminous pigment increases, but at 4%, the light transmittance is slightly deteriorated, and at 5%, the light transmittance is almost nil. In the case of 0.5%, the light transmittance is good, but the afterglow luminance is very low, and the visibility in darkness is considerably poor. From the above, it is preferable that the ratio of the luminous pigment is 1% to 4% by weight in order to obtain a high afterglow luminance and a high light transmittance as a resin molded article containing the luminous pigment.

[0008]

[Table 2]

×: The background on the opposite side is hardly visible from the viewing direction surface of the plate. □: The background on the opposite side is slightly visible from the viewing direction surface of the plate. □: The background on the opposite side is clearly visible from the viewing direction surface of the plate. Afterglow luminance: Above the relative afterglow luminance in the dark after irradiating fluorescent light or sunlight, as described above, remove or reduce fine pigments of luminous pigments, increase the ratio of coarse pigments, and In addition to increasing the afterglow brightness in the dark of the resin molded product to improve visibility, the background on the opposite side of the resin molded product can be seen in a bright place.

[0010] In addition to polycarbonate, acrylic (PMMA), polypropylene, AS
Resin, vinyl chloride, polystyrene, urethane resin,
Similar results are obtained for all permeable resins such as polyethylene. If these resins containing luminous pigments are used for the exterior of mobile phones, watches, audio, game consoles, remote controls, etc., they can emit light in the form of dots in the dark to enhance visibility and enjoy the appearance. Can be seen through.

[0011]

As described above, according to the present invention,
By mainly using coarse phosphorescent pigments in the resin containing phosphorescent pigments, compared to those containing many phosphorescent pigments with a fine particle size, if the content of the same amount of phosphorescent pigment is used, resin molded products Not only improves the light transmittance, but also increases the afterglow luminance. Therefore, by using the resin containing the luminous pigment of the present invention for the exterior component, the interior wrapped in the exterior component can be seen through, and the visibility of the exterior component in the dark can be improved.

[Brief description of the drawings]

FIG. 1 is a top view of a resin molded product containing a luminous pigment of the present invention.

FIG. 2 is a top view of a conventional resin molded product containing a luminous pigment.

[Explanation of symbols]

 1 resin 2 luminous pigment

Continued on front page F term (reference) 4F071 AA01 AA50 AB01 AB18 AC01 AF29 AF30 AF33 BC04 BC17 4H001 CA01 4J002 AA001 BB031 BB121 BC031 BC061 BD041 BG061 CG001 CK021 DE046 DE096 DE146 FD096

Claims (3)

[Claims] 1. A luminous pigment having a particle diameter of 20 μm or more is 1% to 4% by weight, a luminous pigment having a particle diameter of less than 20 μm is 1% or less by weight, and 1% by weight of the entire luminous pigment. A translucent luminous resin, wherein a luminous pigment is mixed or contained in the resin so as to be at least 4%. 2. A molded article of a translucent luminous resin using the translucent luminous resin according to claim 1. 3. The molded article of translucent luminous resin according to claim 1, wherein the translucent luminous resin is used for the outer case.