JP2000162417A - Retrorefletion sheet and safety article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a retroreflection sheet capable of having sufficient retroreflection efficiency even if light is incident at a slant low angle, and to obtain a bicycle/motorcycle component, various safety products, a security product, an indicator, or the like. SOLUTION: This retroreflection sheet for a bicycle/motorcycle component, a safety product, a security product, an indicator, or the like, satisfies the following conditions (1), (2). (1) Nearly square blocks are arranged in lines and rows with no space, preferably in a checkered pattern, while a pair of triangular pyramidal cube corner retroreflection elements having isosceles triangular bottoms are disposed in each the nearly square block in the most densely filling state. (2) The pair of the triangular pyramidal cube corner retroreflection elements are disposed in an equal aligning direction in one nearly square block, while the sheet has at least one nearly square block having a different aligning direction from the other nearly square blocks.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retroreflective sheet and a safety article using the same, and more particularly, to a safety vest, a safety belt, an armband, and the like used at night work sites and the like. The present invention relates to a sheet having light reflectivity in multiple directions and a safety article to which the sheet is attached.

[0002]

2. Description of the Related Art Conventionally, a retroreflective sheet for reflecting incident light back toward a light source has been used at night at construction sites by attaching it to safety vests, safety belts, armbands, and the like. By reflecting light and the like and shining, the presence of workers and equipment is notified, which contributes to the execution of safe work.

[0003] Such retroreflective sheets are broadly classified according to their structure, and are classified into a bead type in which micro glass beads are used as a reflector material, and a micro prism type in which a triangular pyramid-shaped cube corner is formed on the sheet itself. . In these, the micro prism type is often used because of its generally high luminance. By the way, in this micro prism type, the optical axis of the triangular pyramid-shaped cube corner retroreflective element (the axis at an equal distance from the three planes forming an angle of 90 degrees with each other) is considered from the principle of reflection. ) And the incident light beam exhibit good retroreflectivity in a range where the angle (ie, the incident angle) is small, but when the incident angle is large, that is,
When light is incident from an obliquely low angle, the condition of internal total reflection determined by the ratio of the refractive index of the material constituting the element to the refractive index of air is not satisfied, and the incident light is totally reflected at the interface of the element. However, there is a problem in that the light is transmitted without being reflected and the retroreflection efficiency is rapidly reduced. Thus, the narrow divergence angle of the retroreflected light is, for example, difficult to reach the eyes of a driver located away from the optical axis when the light emitted from the headlamp of the automobile is retroreflected by the traffic sign. That has been pointed out as a very serious disadvantage in practical use.

[0004] In order to cope with such inconvenience, for example, in Japanese Patent Application Laid-Open No. H10-123309, it is not to use a right-angled triangular pyramid, but to use a cube corner in which the apex is inclined at a fixed angle, that is, the base is an isosceles triangle. Has been proposed,
Even in this case, the problem that it is difficult to obtain sufficient total reflection in directions other than the specific range because the inclination of the vertex is constant has not been solved. Furthermore, it has been proposed to improve the reflectivity by depositing aluminum or silver on the back surface of the cube corner, but at the same time as the problem of high cost, the oxidation of these metals darkens the reflective surface and conversely increases the efficiency. Has been pointed out.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above point of view, and provides a retroreflection method capable of obtaining a sufficient retroreflection efficiency even when light enters from an obliquely low angle. An object of the present invention is to provide a safety sheet and various safety articles using the sheet.

[0006]

Means for Solving the Problems As a result of diligent studies on the above-mentioned problems, the present inventors have found that a cube corner having a bottom surface having an isosceles triangle shape and a pattern in which the isosceles triangle faces in different directions is used. Have been found to be able to achieve the above object by arranging them in a checkered pattern, and have completed the invention.

That is, the present invention provides a retroreflective sheet defined in the following (1) to (5) and various safety articles to which the retroreflective sheet is adhered or directly used as a material. (1) A retroreflective sheet satisfying the following (A) to (C). (A) Substantially square blocks each having a side length of 2 to 6 mm are lined up in the vertical and horizontal directions without gaps, and a pair of triangular pyramid-shaped cube corner retroreflective elements are included in the one substantially square block. Are arranged in a close-packed state. (B) The pair of triangular pyramidal cube corner retroreflective elements each have a substantially isosceles triangular bottom surface on one plane (XX ′), and protrude from the same side of the surface. The substantially isosceles triangles forming the bottoms share the bases of the triangles and are located at substantially symmetric positions. (C) The arrangement direction of a pair of triangular pyramidal cube corner retroreflective elements in the substantially square block of (A) is the same in one substantially square block, but the sheet is formed. Has at least one substantially square block whose arrangement direction is different from the others. (2) A retroreflective sheet satisfying the following (A) to (C). (A) Substantially square blocks each having a side length of 2 to 6 mm are lined up in the vertical and horizontal directions without gaps, and a pair of triangular pyramid-shaped cube corner retroreflective elements are included in the one substantially square block. Are arranged in a close-packed state. (B) The pair of triangular pyramidal cube corner retroreflective elements each have a substantially isosceles triangular bottom surface on one plane (XX ′), and protrude from the same side of the surface. The substantially isosceles triangles forming the bottoms share the bases of the triangles and are located at substantially symmetric positions. (C) The arrangement direction of a pair of triangular pyramid-shaped cube corner retroreflective elements in the substantially square block of (A) is the same in one substantially square block. The shared base in (B) is (18 ′) on the plane (XX ′).
It belongs to one of n (n is a natural number of 2 or more) arrangement patterns distributed in a relationship of being rotated by 0 / n) degrees. (4) In (C) according to (2), there are six types of substantially square blocks in which the shared base in (B) is rotated by 30 degrees on the plane (XX ′). The retroreflective sheet according to the above (2), wherein the retroreflective sheet belongs to any of the arranged patterns.

(1) Expressed in the direction of one common base in the above (B), the common base is 0 degree clockwise with respect to a reference line drawn up and down on the plane (XX ′). (2) Similarly, the one whose base is rotated clockwise by 30 degrees (hereinafter, referred to as “second pattern”) (3) The one whose base is rotated clockwise by 60 degrees (hereinafter referred to as "third pattern") (4) Similarly, the base whose base is rotated clockwise by 90 degrees (hereinafter "the third pattern") (5) Similarly, the bottom is located at a position rotated clockwise by 120 degrees (hereinafter referred to as “fifth pattern”). (6) Similarly, the bottom is clockwise by 150 degrees. At the rotated position (hereinafter referred to as "sixth pattern") (5) Above The retroreflective sheet according to (1), wherein in (1) and (A), the arrangement of the substantially squares is in a checkered pattern. (6) At least one kind of article selected from bicycle parts or motorcycle parts, safety articles, security articles, or signs to which the retroreflective sheet according to any one of (1) to (5) is attached. (7) At least one article selected from safety articles, security articles, and signs using the retroreflective sheet according to any one of (1) to (5) above as a material thereof. (8) The bicycle or motorcycle part according to (6), wherein the bicycle or motorcycle part is at least one selected from a handle, a frame, a mudguard, a wheel, and a luggage basket. (9) The safety supplies include a safety vest, a safety jumper, a safety kappa, a safety key, a safety belt, a safety wristband, a safety arm band, a safety armband, a safety hat,
The safety article according to (6) or (7), which is one kind selected from safety gloves, safety watches, safety umbrellas, safety shoes, safety badges, safety key chains, and safety accessories. (10) The security article is one selected from the group consisting of a signal light, a barricade, a pipe cushion, a color cone, a cone bridge, a cone bar, a reflective tape, a security light, a tube light, a lily of the valley lamp, and an internal light. ) Or the security article according to (7). (11) The sign according to (6) or (7), wherein the sign is one selected from a road sign, a banner, a flag, and a banner.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings, but the invention is not limited to the shapes shown in the drawings. 1. Retroreflective sheet (1) The retroreflective sheet according to the present invention satisfies the following (A) to (C). (A) The length of one side is 2 to 6 mm, preferably 3 to 5 mm
Are arranged in a vertical and horizontal direction without any gap, preferably in a checkered pattern, and a pair of triangular pyramid-shaped cube corner retroreflective elements is closely packed in the one substantially square block. They are arranged in a state.

The substantially square blocks need to be arranged in the vertical and horizontal directions without any gaps, but the arrangement is not particularly limited. Specifically, it is preferable to arrange them in a so-called checkered pattern as shown in FIG. The pair of triangular pyramidal cube corner retroreflective elements is as described later.

The close-packed state is not particularly limited as long as it is arranged in the highest density. Specifically, as shown in FIG. 3, it means a state in which the parts are continuously arranged without gaps. . (B) The pair of triangular pyramidal cube corner retroreflective elements each have a substantially isosceles triangular bottom surface on one plane (XX ′), and protrude from the same side of the surface. The substantially isosceles triangles forming the bottoms share the bases of the triangles and are located at substantially symmetric positions.

The pair of triangular pyramidal cube-corner retroreflective elements is specifically as shown in FIG. The shape of the above approximately isosceles triangle is not particularly limited. That is, the included angle of the isosceles may be an acute angle or an obtuse angle. It is preferably an acute angle, and more preferably about 40 to 50 degrees. However, if the angle is an obtuse angle, the number of triangular pyramidal cube-corner retroreflective elements that are closest packed in one of the substantially square blocks may be reduced. Also, 60
The case of the degree is not preferable because it becomes an equilateral triangle instead of an isosceles triangle, and this case is excluded from the present invention.
The size of the substantially isosceles triangle is not particularly limited, but the length of one side of the isosceles is preferably 0.25 to 0.30 mm, and the length of the base is preferably 0.20 to 0.30 mm. 25 mm.

The height of the triangular pyramid whose apex protrudes on the same plane side is not particularly limited, but from the viewpoint of convenience in embossing when forming a sheet.
0.08 to 0.15 mm is preferred. (C) The arrangement direction of a pair of triangular pyramidal cube corner retroreflective elements in the substantially square block of (A) is the same in one substantially square block, but the sheet is formed. Has at least one substantially square block whose arrangement direction is different from the others.

If all the substantially square blocks forming the sheet have the same arrangement of the triangular pyramidal cube corner retroreflective elements, the reflection may be biased, which is not preferable. If there is at least one substantially square block in which the arrangement direction is different from the other, the presence of the substantially square block contributes to reflection of light in different directions and reflects light in all directions as a whole sheet. Becomes possible. It is desirable that the number of substantially square blocks whose arrangement direction is different from the others is as large as possible. Further, it is preferable that the substantially square blocks having the same arrangement direction are not continuously arranged or unevenly arranged, but are arranged at dispersed positions. (2) The retroreflective sheet according to the present invention also satisfies the following (A) to (C). (A) and (B) have the same contents as above. (C) The arrangement direction of a pair of triangular pyramid-shaped cube corner retroreflective elements in the substantially square block of (A) is the same in one substantially square block. The shared base in (B) is (18 ′) on the plane (XX ′).
It belongs to one of n (n is a natural number of 2 or more) arrangement patterns distributed in a relationship rotated by 0 / n degrees.

In other words, the arrangement direction of the pair of triangular pyramid-shaped cube corner retroreflective elements in the substantially square block of (A) is the same in one substantially square block, but is substantially the same. Each square block belongs to one of the following n patterns (n is a natural number of 2 or more) in a distributed manner. (1) When expressed in the direction of one common base in the above (B), the base is rotated clockwise by 0 ° with respect to a reference line drawn up and down on the plane (XX ′). (1) Similarly, the bottom side is clockwise and angled (18)
0 (n) degrees (hereinafter referred to as “second pattern”) (3) Similarly, the one base is clockwise, and the angle is ｛(1)
80 / n) × 2 ° rotated position (hereinafter referred to as “third pattern”).
1) Rotate up to times.

(N) Similarly, the one bottom side is at a position rotated clockwise by {(180 / n) × (n-1)} degrees (hereinafter referred to as an “n-th pattern”). The case where n is 6 will be described as follows. (1) Expressing in the direction of one common base in (B), the common base is rotated clockwise by 0 degrees with respect to a reference line drawn up and down on the plane (XX ′). (2) Similarly, one of the bases is rotated clockwise by 30 degrees (hereinafter, referred to as a "second pattern"). (3) Similarly, the first pattern is a second pattern. One whose bottom is rotated clockwise by 60 degrees (hereinafter referred to as “third pattern”) (4) Similarly, one whose bottom is rotated by 90 degrees clockwise (hereinafter “fourth pattern”) (5) Similarly, the one whose base is rotated clockwise by 120 degrees (hereinafter referred to as a “fifth pattern”) (6) Similarly, the base is rotated clockwise by 150 degrees At the position (hereinafter referred to as “sixth pattern”) This will be described in detail below.

In the above-mentioned "first pattern", the "position rotated clockwise by 0 degrees" means that the rhombus formed by two isosceles triangles which share the bases of each other and are substantially symmetrical. This is a so-called “sleeping side by side” state. In addition, the above “position rotated 30 degrees clockwise”
That is, it means a state of being rotated clockwise by 30 degrees with respect to the state of "sleeping right beside". Similarly, the "position rotated clockwise by 60 degrees" means a state rotated clockwise by 60 degrees with respect to the state of "sleeping right beside".

Similarly, the "position rotated clockwise by 90 degrees" means a state rotated clockwise by 90 degrees with respect to the state of "sleeping right beside". In other words, , The rhombus is “standing upright”.
Incidentally, the one rotated by 180 degrees is the same as the one rotated by 0 degrees. As described above, the substantially square blocks belong to any one of the six arrangements rotated in an angle of 0 to 30 degrees.

Further, in the above-described first to sixth patterns of substantially square blocks, it is desirable that substantially square blocks of the same pattern are arranged without being adjacent to each other in the vertical direction and / or the horizontal direction. More preferably, in both the vertical direction and the horizontal direction, it is desirable that substantially square blocks of the same pattern are arranged without being adjacent to each other.

It is sufficient that substantially square blocks of the same pattern are not adjacent to each other in the vertical direction and / or the horizontal direction. There is no particular limitation on the arrangement, but preferably the arrangement shown in FIG. , Are arranged in a repetition of their basic arrangement. That is, in the horizontal direction, the “third pattern” is arranged next to the “first pattern”, the “fifth pattern” is arranged next to the “first pattern”, and the “first pattern” is arranged next to the “third pattern”. As described above, the arrangement of the “first pattern”, the “third pattern”, and the “fifth pattern” is continuously arranged based on the basic arrangement. Further, in the row one row below where the “first pattern”, “third pattern” and “fifth pattern” are arranged, the “fourth pattern” is next to the “second pattern” in the horizontal direction. The "second pattern", the "fourth pattern", and the "sixth pattern" are arranged so that the "sixth pattern" is arranged next to the "second pattern" and the "second pattern" is arranged next to the "sixth pattern".
Are arranged consecutively with the basic arrangement. In a row one row below, the above-mentioned “first pattern”, “third pattern”, and “fifth pattern” are arranged in the horizontal direction, and the “first pattern”, “third pattern”, and “ 5 patterns ”and the above“ second pattern ”,
Rows composed of “fourth pattern” and “sixth pattern” are alternately arranged.

Although the case where n is 6 has been described in detail above, even when n is a natural number other than 6, substantially square blocks of the same pattern may be adjacent in the vertical and / or horizontal directions. It is desirable to be arranged without.
More preferably, in both the vertical and horizontal directions,
It is desirable that substantially square blocks of the same pattern are arranged without being adjacent to each other. 2. Method for Producing Retroreflective Sheet The method for producing the retroreflective sheet according to the present invention is not particularly limited, and generally, a resin sheet is formed using a mold capable of forming triangular pyramid cube corners. A method of embossing is used.

The material to be used is not particularly limited, but it is desirable that the material has a certain degree of flexibility since it is used by being attached to various articles. In particular,
Polyolefin resins such as polyethylene resins and polypropylene resins, polycarbonate resins, vinyl chloride resins, (meth) acrylic acid resins, epoxy resins, styrene resins, polyester resins, fluororesins, cellulose resins, urethane resins, and the like.

According to the purpose, a surface protective layer may be laminated on the reflective element base layer on which the triangular pyramid cube corner retroreflective elements are arranged, or a printed layer or the like may be further laminated. Is also good. The same resin as the reflective element base layer may be used for the surface protective layer, but an ultraviolet absorber, a light stabilizer, an antioxidant and the like are preferably added. 3. A safety article to which a retroreflective sheet is attached or a safety article to be used as a direct material.

The retroreflective sheet according to the present invention is attached to various articles or used directly as a material. That is, since the retroreflective sheet according to the present invention can efficiently reflect light, safety and security articles such as clothes and wearing articles worn at the time of work at night construction sites and the like, signs It is preferably used for such purposes. Furthermore, if it is attached to parts such as bicycles and motorcycles, it is easy to inform the driver of its presence even at night, and safety can be improved.

Specifically, the bicycle part or the motorcycle part includes a handle, a frame, a mudguard, a wheel,
Luggage baskets and the like. In addition, as safety products, safety vests, safety jumpers, safety kappa, safety tusks, safety belts, safety wristbands, safety arm bands, safety armbands, safety hats, safety gloves, safety watches,
Examples include safety umbrellas, safety shoes, safety badges, safety key chains, safety accessories, and the like. Examples of security supplies include signaling lights, barricades, pipe cushions, color cones, cone bridges, cone bars, reflection tapes, security lights, tube lights, lily of the valley lamps, and internal lighting. Furthermore, signs include road signs, banners,
Flags, banners and the like.

For use in these, the sheet may be cut into an appropriate size and shape according to the purpose, and then attached. When attaching the sheet, an adhesive may be applied to the back surface of the sheet or may be directly sewn. Further, the sheet may be cut directly into a desired shape instead of being attached to these articles.

[0027]

[Example 1]

(1) Evaluation method 1 A pair of triangular pyramid cube corner retroreflective elements have a shape as shown in FIG. 6, and each side of a substantially square block is 4 mm. A retroreflective sheet, which is arranged as shown in FIG. 5, was attached to the entire surface of the safety vest body, and a person wearing the safety vest was allowed to stand alone at night. Next, the monitor was placed on the passenger car, and the wearer of the safety vest was visually recognized on the monitor. The monitor positions are as follows.

Linear distance between the monitor and the wearer of the safety vest: 100 m Horizontal distance between the monitor and the wearer of the safety vest:
5m Distance from car lamp to monitor eye level:
A test was conducted by 10 persons as an 80 cm monitor to check the visibility. Table 1 shows the results.

In each of the monitors from Example 1 to Comparative Example 3, four points were the most visible, three points were the next most visible, and two points were the next most visible.
The points that were inferior were given the score of 1 point, the scores given by 10 monitors were totaled, and the four examples of Example 1 to Comparative Example 3 were ranked 1st to 4th respectively. . The first place was represented by ◎, the second place was represented by ○, the third place was represented by Δ, and the fourth place was represented by ×.

[0030]

[Table 1]

(2) Evaluation method 2 Evaluation method 1 was carried out in the same manner as evaluation method 1 except that the linear distance between the monitor and the wearer of the safety vest was set to 50 m. Table 1 shows the results. (3) Evaluation method 3 In the evaluation method 1, a test was conducted by placing the monitor on a dump truck instead of a passenger car. At this time, the distance from the dump truck ramp to the eye level of the monitor is 1
It was 50 cm. Other than that, it carried out similarly to the evaluation method 1.

The results are shown in Table 1. (4) Evaluation method 4 Evaluation method 3 was performed in the same manner as evaluation method 3 except that the linear distance between the monitor and the wearer of the safety vest was set to 50 m. Table 1 shows the results. [Comparative Example 1] In the same manner as in Example 1 except that a bead-type reflector (manufactured by Sumitomo 3M, "Scotchlite") was used instead of the retroreflective sheet according to the present invention,
Evaluation was performed similarly.

The results are shown in Table 1. [Comparative Example 2] Not a retroreflective sheet according to the present invention but a retroreflection using a regular triangular pyramid-shaped (bottom is not an isosceles triangle but a regular triangle) cube corner (Reflectsite S200 grade). Except for using the conductive sheet, the same procedure as in Example 1 was performed, and the evaluation was performed in the same manner.

Table 1 shows the results. [Comparative Example 3] Instead of the retroreflective sheet according to the present invention, the cube corners whose bottoms are isosceles triangles but all face the same direction (Sumitomo 3M,
The evaluation was performed in the same manner as in Example 1 except that a retroreflective sheet using "high gloss") was used.

The results are shown in Table 1.

[0036]

According to the present invention, it is possible to obtain a retroreflective sheet capable of obtaining a sufficient retroreflective efficiency even when light is incident from an obliquely low angle and various safety articles to which the sheet is attached. .

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a checkered pattern

FIG. 2 is an elevation view and a front view of a pair of triangular pyramidal cube corner retroreflective elements according to the present invention.

FIG. 3 is an example of close packing of a triangular pyramidal cube corner retroreflective element according to the present invention.

FIG. 4 is a diagram illustrating six patterns of directions of a triangular pyramid-shaped cube corner retroreflective element when n is 6.

FIG. 5 is an example of a basic arrangement of substantially square blocks when n is 6;

FIG. 6 is an elevation view and a front view of a pair of triangular pyramid-shaped cube corner retroreflective elements in the embodiment.

[Explanation of symbols]

11: substantially square block 21: elevation view of a pair of triangular pyramid-shaped cube corner retroreflective elements 22: front view of a pair of triangular pyramid-shaped cube corner retroreflective elements 41: first pattern 42: second pattern 43: third Pattern 44: Fourth pattern 45: Fifth pattern 46: Sixth pattern 51: Substantially square block of first pattern 52: Substantially square block of second pattern 53: Substantially square block of third pattern 54: Abbreviation of fourth pattern Square block 55: Fifth pattern substantially square block 56: Sixth pattern substantially square block 61: Length of one side in substantially isosceles triangle: 0.2
80 mm 62: Base length of approximately isosceles triangle: 0.2
30 mm 63: height of a pair of triangular pyramidal cube corner retroreflective elements 0.103 mm

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D064 AA12 AA15 AA22 BA01 BA03 CA03 DA05 DA16 EB22 EB34 JA01 2H042 EA04 EA15 EA16 EA17 EA20

Claims (11)

[Claims] 1. A retroreflective sheet satisfying the following (A) to (C). (A) Substantially square blocks each having a side length of 2 to 6 mm are lined up in the vertical and horizontal directions without gaps, and a pair of triangular pyramid-shaped cube corner retroreflective elements are included in the one substantially square block. Are arranged in a close-packed state. (B) The pair of triangular pyramidal cube corner retroreflective elements each have a substantially isosceles triangular bottom surface on one plane (XX ′), and protrude from the same side of the surface. The substantially isosceles triangles forming the bottoms share the bases of the triangles and are located at substantially symmetric positions. (C) The arrangement direction of a pair of triangular pyramidal cube corner retroreflective elements in the substantially square block of (A) is the same in one substantially square block, but the sheet is formed. Has at least one substantially square block whose arrangement direction is different from the others. 2. A retroreflective sheet satisfying the following (A) to (C). (A) Substantially square blocks each having a side length of 2 to 6 mm are lined up in the vertical and horizontal directions without gaps, and a pair of triangular pyramid-shaped cube corner retroreflective elements are included in the one substantially square block. Are arranged in a close-packed state. (B) The pair of triangular pyramidal cube corner retroreflective elements each have a substantially isosceles triangular bottom surface on one plane (XX ′), and protrude from the same side of the surface. The substantially isosceles triangles forming the bottoms share the bases of the triangles and are located at substantially symmetric positions. (C) The arrangement direction of a pair of triangular pyramid-shaped cube corner retroreflective elements in the substantially square block of (A) is the same in one substantially square block. The shared base in (B) is (18 ′) on the plane (XX ′).
It belongs to one of n (n is a natural number of 2 or more) arrangement patterns distributed in a relationship rotated by 0 / n degrees. 3. The method according to claim 2, wherein the substantially square blocks having the same pattern are arranged without being adjacent to each other in a vertical direction and / or a horizontal direction. Retroreflective sheet. 4. The (C) according to claim 2, wherein the substantially square block has six relations in which the shared base in (B) is rotated by 30 degrees on the plane (XX ′). 3. The retroreflective sheet according to claim 2, wherein the retroreflective sheet belongs to any one of the following arrangement patterns. 5. The retroreflective sheet according to claim 1, wherein the arrangement of the substantially squares is a checkerboard pattern. 6. At least one article selected from bicycle parts or motorcycle parts, safety articles, security articles, or signs to which the retroreflective sheet according to claim 1 is attached. 7. At least one article selected from safety articles, security articles, and signs using the retroreflective sheet according to claim 1 directly as its material. 8. The bicycle component or the motorcycle component,
The bicycle part or the motorcycle part according to claim 6, which is at least one selected from a handle, a frame, a mudguard, a wheel, and a luggage basket. 9. The safety article includes a safety vest, a safety jumper, a safety kappa, a safety key, a safety belt, a safety wristband, a safety arm band, a safety armband, a safety hat, a safety glove, a safety watch, The safety article according to claim 6, wherein the safety article is one selected from a safety umbrella, safety shoes, a safety badge, a safety key ring, and a safety accessory. 10. The security product is one selected from a signal light, a barricade, a pipe cushion, a color cone, a cone bridge, a cone bar, a reflective tape, a security light, a tube light, a lily of the valley lamp, and an interior light. Item 8. The security article according to Item 6 or 7. 11. The signs may be road signs, banners,
The sign according to claim 6 or 7, wherein the sign is one selected from a flag and a flag.