JP2002363932A - Transfer type reflection material for road surface marker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide transfer type reflection material for an all weather type road surface marker which has sufficient reflection brightness to light beams of headlights incidental at a large angle, and which functions even in rain. SOLUTION: Glass beads of a relatively large diameter (with a refraction factor of 1.85-2.2) are embedded in a sheet type temporary support body in such a way that their hemispheres are exposed. A retroreflective layer is provided on the exposed hemispheres to provide this transfer type reflection material for a road surface marker.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road marking reflector, and more particularly to an all-weather road surface having a high retroreflection luminance for light rays incident at a large angle and having a high reflection luminance even at night in rainy weather. The present invention relates to a reflecting material for marking.

[0002]

2. Description of the Related Art Retroreflective materials are used as road markings and road markings. This is to apply glass beads before the paint applied on the road surface solidifies, and to make the paint on the back surface of the glass beads retroreflective as a reflection surface, so that it can be visually recognized even at night. However, if the marking surface is covered with a water film during rainy weather, the upper hemisphere portion of the glass beads that is exposed to the atmosphere from the coating film surface and has a reflective function will be submerged, and the retroreflective function will be impaired. There is a disadvantage that visibility is significantly deteriorated.
Although this method is effective for incident light having a small angle, retroreflection is very weak for incident light of 60 ° or more due to headlights. Further, the reflection is made by using a white paint or the like in contact with the glass sphere, so that the diffusion is large, and the reflection luminance is inferior to that of the metal evaporation method.

[0003]

The conventional road marking reflector exhibits a certain degree of visibility when the light from the headlight of a vehicle traveling at night is at an angle of 45 ° or less with respect to the road marking surface. Light from the sign is usually 60 °
The retroreflective luminance is very weak because the light is incident at ~ 90 °. Moreover, since the retroreflective function is impaired by the water film in rainy weather, the sign cannot be visually recognized, which is dangerous. For this reason, development of a material that can be retroreflected even at a large incident angle and that functions even in rainy weather has been awaited. SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the above-described conventional road marking reflectors, and is intended to solve the problem that the road marking reflectors are incident at a large angle of 60 ° or more which is required in normal use. The present invention provides an all-weather road marking reflective material that has a sufficient reflection luminance with respect to, and has a high reflection luminance even at night in rainy weather.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a relatively large-diameter glass bead is exposed and embedded in a sheet-shaped temporary support, and a small-diameter glass bead is exposed in the exposed hemisphere. A retroreflective layer composed of a resin layer for holding glass beads, small-diameter glass beads, a resin layer for focus adjustment, and a metal deposition layer is formed to constitute a transfer reflective material for road marking, thereby solving the above-mentioned problems.

[0005] In addition to the above means, a relatively large diameter glass bead having a refractive index of 1.85 to 2.2 is provided to form a transfer reflecting material for road marking to solve the above-mentioned problems.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described. FIG. 1 is a schematic cross-sectional view of a transfer type reflective material 1 for marking a road surface, which comprises a sheet-like temporary support 2, large-diameter beads 3, and a retroreflective layer 4. FIG. 2 shows the large-diameter glass beads 3 and the retroreflective layer 4 in more detail. The retroreflective layer 4 is composed of small-diameter glass beads 5, a small-diameter glass bead holding resin layer 6, a focusing resin layer 7, and a metal-deposited reflection layer 8. The resin layer 6 in the retroreflective layer 4 has transparency and adheres the small-diameter glass beads 5 to the large-diameter glass bead hemisphere 3. The resin layer 7 is transparent and is necessary for focus adjustment for improving retroreflection performance, and is formed in a hemispherical shape, and its surface is vacuum-deposited with aluminum to form a mirror surface. The diameter of the large-diameter glass beads 3 is about 1 mm, and the diameter of the small-diameter glass beads 5 is about 50 μm. The present invention is configured as described above.

FIG. 3 shows a construction example using the product of the present invention. The transparent resin 9 as an adhesive is applied on the paint 10 of the sign applied on the road 11, and the transfer-type reflective material 1 is stuck thereon, and the sheet-like temporary support 2 is peeled off after being solidified. However, if this treatment is applied to the entire surface of the sign, the color of the paint applied below cannot be seen, so that the reflection material should not be spread tightly. The reason for using a transparent adhesive is that precision is not required for the adhesive application operation.

Next, the operation of the present invention will be described. FIG.
FIG. 4 shows how the small-diameter glass beads 5 held by the transparent resin 6 are retroreflected in the retroreflective layer 3. Since the glass beads 5 are in contact with the resin 6, even if glass having a high refractive index is used, the ratio of the refractive indexes is still insufficient, and the focal point goes out of the glass beads 5. For this reason, by providing the focus adjusting resin layer 7 and the metal deposition layer 8, optimal retroreflection is realized. Although the direction of the reflected light varies depending on the angle of incidence of the parallel rays incident on the beads 5, the beads-type retroreflection has a certain degree of diffusion as described above, which is the reason why this method is adopted. That is, since the position of the headlight of the automobile and the position of the driver's eyes are not the same, if strictly retroreflected, the reflected light of the headlight will not enter the driver's eyes. Refractive index n of small diameter glass beads 5
1 increases the ratio of the resin to the refractive index n2, so that n1 = 2.
It is desirable to use about two.

FIG. 5 is for finding a condition for retroreflection when a light beam parallel to the road surface is incident on the large-diameter glass beads 3. Assuming that the incident angle is α and the refraction angle is β, α> 2β is a necessary condition from the figure in order for the incident light beam to hit the retroreflective layer 4. Finding the refractive index at the limit α = 2β Therefore, in order for light rays having an incident angle of 45 ° or more to be retroreflected, a refractive index of 1.85 or more is required. As the upper limit of the refractive index, 2.2 is appropriate from the viewpoint of manufacturing and price.

FIG. 6 illustrates incident light and reflected light when the road is dry, with respect to the retroreflective center light. Since the large-diameter beads 3 and the small-diameter beads 5 of the retroreflective layer 4 have a diameter ratio of 20 or more, when drawn on the scale of the large-diameter beads 3, the reflected light follows substantially the same path as the incident light. As can be seen from the figure, the light is evenly retroreflected to a considerably large angle. FIG. 7 illustrates a state where the beads are submerged in rainy weather. As shown in the figure, in this method, the retroreflection function is not impaired by the water film.

[0011]

The present invention produces the following effects. The light is substantially evenly retroreflected for incident light from 1.0 ° to near 90 °. 2. It works even in the rainy water film. 3. Since the reflective film is metal-deposited, the reflective brightness is higher than that of a conventional white paint. 4. Since it is not a sheet system, there is no worry about peeling. 5. Since the surface of the reflector is made of glass beads, it is robust and hardly scratched.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of the present invention.

FIG. 2 is a partially enlarged view of the present invention.

FIG. 3 is a sectional view of a construction example using the present invention.

FIG. 4 is an explanatory diagram of incident and reflected light rays on a retroreflective layer.

FIG. 5 is an explanatory diagram of conditions under which light rays parallel to a road surface are retroreflected.

FIG. 6 is an explanatory diagram of incident and reflected light rays when the road surface is dried.

FIG. 7 is an explanatory diagram of incident and reflected light rays when submerged in rainy weather.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transfer reflective material for road marking 2 sheet-like temporary support 3 large-diameter glass bead 4 retroreflective layer 5 small-diameter glass bead 6 small-diameter glass bead holding resin layer 7 focus adjusting resin layer 8 metal vapor deposition layer 9 resin layer 10 paint layer 11 Road surface layer 12 Incident light parallel to the road surface 13 Water film layer

Claims (2)

[Claims] 1. A resin layer for holding small-diameter glass beads, a small-diameter glass bead, and a resin layer for focusing, wherein relatively large-diameter glass beads are exposed and embedded in the sheet-like temporary support for a hemisphere. And a retroreflective layer for road marking, wherein the retroreflective layer comprises a metal deposited layer. 2. The transfer reflective material for road marking according to claim 1, wherein said relatively large-diameter glass beads have a refractive index of 1.85 to 2.2.