JPH06280221A - Road marking material - Google Patents

Abstract

PURPOSE:To improve retroreflectivity by a method wherein protuberances and dents are alternately formed at fixed intervals to a surface layer to which glass beads are stuck, and the length for the protuberance and the dent is selected with the ratios within the specified limits. CONSTITUTION:The surface layer serving as a sheet base 12 for a road marking material 10 is made by mixing filling material and glass beads or the like uniformly with heating at high temperature applied. An adhesive layer 16 available for sticking to asphalt roads or concrete roads is layered to the reverse side of the sheet base 12, and a strippable sheet 18 with its surface coated with silicon or the like is temporarily attached to the surface of the adhesive layer 16. Then, protuberances 20 and dents 22 are alternately formed at fixed intervals to the surface of the sheet base 12 in its longitudinal direction. The protuberance and the dent are formed so that the length thereof become in relative ratios from 1: 0.4 to 1: 1. As the surface is made of glass beads formed in unevenness, it has improved retroreflectivity as compared with conventional road marking materials, for which glass beads are dispersed on flat surface, and the road marking material with such surface becomes conspicuous.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a road marking material,
In particular, it relates to road marking materials such as road center lines, pedestrian crossings, and instruction lines.

[0002]

2. Description of the Related Art Conventionally, road marking materials in which glass beads are mixed on a flat surface have been known. Such a road marking material has a high retroreflectivity and is more conspicuous as compared with other materials not sprayed with glass beads, and was suitable as a road marking material.

[0003]

However, due to the need to prevent accidents and the like, it is desired to develop a road marking material having a higher retroreflectance and being more conspicuous.

Therefore, a main object of the present invention is to provide a road marking material having glass beads fixed thereon, which can further improve the retroreflectivity.

[0005]

According to the present invention, irregularities are alternately formed on a surface layer to which glass beads are fixed at regular intervals and the ratio of the lengths of the irregularities is 1: 0.4-1. : 1
It is a road marking material selected for.

[0006]

[Function] Due to the unevenness, a surface intersecting the horizontal plane is formed. When light is incident on the horizontal surface and the intersecting surface, reflection occurs on each surface, and the amount of light returning from the latter is larger from the latter, so that the retroreflectivity is increased as a whole.

[0007]

According to the present invention, since the surface is a glass bead surface having an uneven surface, compared to a conventional road marking material in which glass beads are simply scattered on a flat surface,
The retroreflectivity is improved, and a highly visible road marking material can be obtained.

The above-mentioned objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings.

[0009]

1 is a perspective view showing an embodiment of the present invention. The road marking material 10 includes a belt-shaped surface layer, that is, a sheet base material 12. The sheet base material 12 is, for example, a material in which thermoplastic elastomer, petroleum-based synthetic resin, coloring pigment, filler such as calcium carbonate, glass beads, and the like are heated to high temperature and uniformly mixed. In addition,
As shown in FIG. 2, some of the glass beads 14 are scattered near the surface of the sheet substrate 12 while being partially exposed from the surface of the sheet substrate 12.

On the back surface of the sheet substrate 12, a pressure-sensitive adhesive layer 16 that can be attached to an asphalt road or a concrete road is laminated. Further, a release sheet 18 having a surface coated with silicon or the like is temporarily attached to the adhesive layer 16. The release sheet 18 is removed when the road marking material 10 is attached to a road surface (not shown).

On the surface of the sheet base material 12, peaks and valleys are alternately formed at regular intervals in the length direction. The lengths of the peaks or protrusions 20 and the valleys or recesses 22 are indicated by A and B in the length direction of the sheet base material 12, respectively, as shown in FIG. The thicknesses of the convex portion 20 and the concave portion 22 are indicated by C and D, respectively.
The length A of the convex portion 20 and the length B of the concave portion 22 are formed such that the relative lengths thereof are in the range of 1: 0.4 to 1: 1. Further, preferably, the thickness C of the convex portion 20 and the thickness D of the concave portion 22 are formed in a relative ratio range of 2.0: 1.5 to 7.0: 1.5. .

Regarding the uneven shape of the sheet base material 12, as shown in FIG. 3, the convex portion 20 is formed in a so-called substantially trapezoidal shape. Further, as another modification of the sheet base material 12, as shown in FIG.
It is possible that the surface formed by the above is orthogonal to the horizontal plane, and that the convex portion 20 and the concave portion 22 are formed in a corrugated shape as shown in FIG.

According to the present invention, by appropriately selecting the ratio of A and B as described above, the retroreflectance of the glass beads is increased to make it easier to see.

In the above embodiments, the sheet sticking type road marking material has been described. However, the present invention can also be easily applied to a road marking material, for example, of a melting type or a paint type, in which irregularities can be appropriately formed on the surface.

Experimental Example I In Experimental Example I, a thermoplastic elastomer, a petroleum-based synthetic resin, a coloring pigment, a filler such as calcium carbonate, glass beads, and the like were mixed at a predetermined mixing ratio, and heated at high temperature to obtain a mixture in a molten state. made. Next, while molding the mixture in the molten state as shown in FIG. 1, glass beads were fixed on the surface in an appropriate amount. The particle size of this glass bead
For example, the thickness is 420 to 840 μm, and the refractive index is 1.
As 90, measurement samples 1 and 2 were obtained.

For sample Nos. 1 and 2, the length A of the convex portion, the thickness C of the convex portion and the thickness D of the concave portion are respectively
The length B of the recess was 50 mm, 2.5 mm and 1.5 mm, and A: B was 1: 1. The measurement sample 2 is a conventional example having a flat surface, that is, a comparative example.

Next, a measurement optical system 24 for measuring the retroreflectance of each of the measurement samples 1 and 2 thus prepared was prepared.

The optical system 24 includes a light source 26 as shown in FIG. The light source 26 has an incident angle of 86 ° with respect to a measurement sample horizontally placed at a position 15 m away.
Light is incident on. The light incident on the sample is retroreflected toward the light source 26 by the glass beads 14 uniformly distributed on the sample surface. A luminance meter 28 is provided above the light source 26. The luminance meter 28 measures the intensity of light retroreflected toward the light source 26 at an observation angle of 0.2 °.

As a measurement procedure in such an optical system 24, first, the illuminance E (lux) on the sample surface is measured. This can be measured by directing the light receiving surface of the sample in the direction of incident light. Next, the luminance L of the sample surface (cd / m ² ) is measured by the luminance meter 28. Based on the measured surface luminance L and surface illuminance E, the retroreflectivity q (m
cd / luxm ² ) is required.

[0020] [Road Material Association Bulletin: No.40, page 10, issued on July 5, 1984]

The retroreflectivity q was measured in a dark room and was measured in each of the dry and wet states. The wet condition is assumed to be during nighttime rainfall.

The results are shown in Table 1.

[0023]

[Table 1]

It can be seen from Table 1 that the measurement sample 1 showed a higher value in both the dry condition and the wet condition than the measurement sample 2 as the conventional example. Thus, by appropriately selecting the length A of the convex portion and the length B of the concave portion, there is an effect of increasing the retroreflectivity.

Experimental Example II In this Experimental Example, measurement samples 3 and 4 were prepared in the same manner as in Experimental Example I described above, and were measured in the same manner. However, the refractive index of the fixed glass beads is changed to 1.52.

The results of this Experimental Example II are shown in Table 2.

[0027]

[Table 2]

In Table 2 as well, it can be seen that the tendency similar to that of Table 1 is exhibited, and that Sample 3 exhibits a larger retroreflectivity as compared with Sample 4 (conventional example).

Experimental Example III In this Experimental Example, measurement samples 5 and 6 were prepared in the same manner as in Experimental Example I described above and measured in the same manner. However, the length A of the convex portion and the length B of the concave portion are twice as long as in Experimental Example I.

The results of Experimental Example III are shown in Table 3.
In Table 3, sample 6 is a conventional example.

[0031]

[Table 3]

Experimental Example IV In this Experimental Example, measurement samples 7 and 8 were prepared in the same manner as in Experimental Example III described above, and were measured in the same manner. However, the refractive index of the glass beads is 1.52.

The results of Experimental Example IV are shown in Table 4. In Table 4, sample 8 is a conventional example.

[0034]

[Table 4]

Thus, according to Experimental Examples I to IV,
It was found that if the ratio of A: B is set to 1: 1, the change in retroreflectance can be improved as compared with the conventional flat one.

Next, in Experimental Examples V and VI, C:
The change in retroreflectance with the ratio of D is measured.

Experimental Example V In Experimental Example V, measurement samples 101 to 108 were prepared in the same manner as in Experimental Example I described above, and were measured in the same manner. However, in this Experimental Example V, C: D was set to 2.0: 1.5, 2.5: 1.5, and A: B for each ratio.
I changed it to 7.0: 1.5.

The results of Experimental Example V are shown in Table 5.

[0039]

[Table 5]

The eight measurement samples 101 to 101 measured here
The retroreflectance of each of 108 is higher than that of the conventional example of sample number 2 in Table 1 in both the dry and wet cases. Thus, it is understood that the effect of improving the retroreflectance due to the unevenness can be exhibited even if C: D changes to some extent.

Experimental Example VI In this Experimental Example, measurement samples 111 to 118 were prepared in the same manner as in Experimental Example V described above, and measurements were conducted in the same manner. However, A and B are each doubled.

The results of this Experimental Example VI are shown in Table 6.

[0043]

[Table 6]

In the following Experimental Examples VII and VIII, the ratio of A: B was further set to 1: 1 or less, and C: D was set.
For the ratio of, the change in retroreflectance at the same ratio as in Experimental Examples V and VI described above is measured.

Experimental Example VII In this Experimental Example, measurement samples 121 to 144 were prepared in the same manner as in Experimental Example V described above and measured in the same manner. However, in this Experimental Example VII, the ratio of A: B was changed from 1: 0.4 to 1: 0.8.

The results of this Experimental Example VII are shown in Table 7.

[0047]

[Table 7]

In Table 7, the same tendency as in Table 5 was shown. In this way, the ratio of A: B is 1: 1 or less: 1:
The ratio was 0.4 to 1: 0.8, and even if C: D changed depending on the ratio, the change in retroreflectance could be improved.

Experimental Example VIII In this Experimental Example, measurement samples 145 to 168 were prepared in the same manner as in Experimental Example VII described above, and the measurement was carried out in the same manner. However, A and B are each doubled.

The results of this Experimental Example VIII are shown in Table 8.

[0051]

[Table 8]

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of FIG.

FIG. 3 is a side view of FIG.

FIG. 4 is an illustrative view for explaining an example of a retroreflectance measuring apparatus of the embodiment in FIG. 1;

FIG. 5 is an illustrative view showing a modified example of the sheet base material of the embodiment in FIG. 1;

FIG. 6 is an illustrative view showing a modified example of the sheet base material of the embodiment in FIG.

[Explanation of symbols]

 10 Road marking material 12 Sheet base material 14 Glass beads 20 Convex portion 22 Recessed portion

Claims (2)

[Claims] 1. A surface layer to which glass beads are fixed, and unevenness formed alternately on the surface layer at regular intervals, wherein the ratio of the length of the unevenness is 1: 0.4 to 1. Road marking material selected as: 1. 2. The ratio of the thickness of the irregularities is 1.5: 2.0.
The road marking material according to claim 1, which is selected in the range of from 1.5 to 7.0.