JP2001318215A - Retroreflective material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retroreflective material, having high retroreflection performance, little decrease in the retroreflection performance by cleaning or dry cleaning, superior resistance to washing and having high durability. SOLUTION: The material consists of a layer of transparent microspheres 1, a fixing resin layer 4 which partially embeds the transparent microspheres 1 to hold them, a reflection layer 3 formed between the transparent microspheres 1 and the fixing resin layer 4, a first transparent resin layer 2 formed to <=20 μm thickness between the transparent microspheres 1 and the reflection layer 3, and a second transparent resin layer 6 applied on the exposed side of the transparent microspheres 1 to air. The second transparent resin layer 6 is formed to have 0.005 to 20 μm thickness at the top of the microsphere 1 and formed into a concentric ellipse to cover the exposed surface of the transparent microsphere 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for decorations of apparel-related members such as clothing, and safety materials such as work clothes. In particular, the present invention has a high retroreflective ability and very excellent washing resistance. The present invention relates to a retroreflective material which is suitable for fashion use by being colored.

[0002]

2. Description of the Related Art Conventionally, a light retroreflective material having glass microspheres attached to a single layer has been widely used for displaying traffic signs and the like, particularly for enhancing visibility at night. However, in recent years, retroreflective materials used in traffic signs have been used to improve safety for people working at night, such as police, fire departments and construction workers. Now used to. In addition, as a measure to prevent traffic accidents for pedestrians, joggers and children at night from the heightened safety awareness of the general public, windbreakers, training wear, sports clothing such as T-shirts and sports shoes, and apparel related to bag decoration etc. Have also become widely used.

The reflective material includes a closed type in which glass microspheres are buried in a resin layer and an open type in which a part of glass microspheres is exposed to air. Since the closed-type light reflecting material is formed by laminating a resin in multiple layers, the number of times that light passes through the resin layer increases, and there is a problem that the reflection performance is reduced due to loss due to light absorption there. In addition, since the resin is laminated, the texture is hard and suitable for traffic signs, but not suitable for clothing. In addition, it is also weak in the washability, which is the fate of clothing, and there has been a problem in that, when washing is performed many times, peeling between resin layers occurs and cracks occur.

[0004] Therefore, an open type retroreflective material in which a part of glass microspheres is exposed to the air has come to be used. These have high light reflectivity, are softer in texture than the closed type, and are excellent in washing resistance, and are now widely used.

However, in recent years, when this open type retroreflective material has been widely used in the field of work clothes, it has come to be used in work clothes of various work fields, and strong dirt adheres thereto. There are also many occasions in which the washing is performed under strong washing conditions. Therefore, there is a demand for an improvement in the washing resistance of the reflector.

As a means of improving the washing property, a method of processing the surface of the open type retroreflective material with a resin to prevent the invasion of chemicals can be considered. Japanese Patent Publication No. 4-11002 proposes to cover a surface of a high refractive index glass sphere having a refractive index of 1.9 or more in a concentric elliptical hemispherical shell shape with a resin having a thickness of 0.01 to 5 μm. However, as described in the embodiment of the present invention, a glass sphere having a medium refractive index of about 1.90 to 1.95, which is usually used in an open type, is used, and the glass sphere is directly used. Even if a reflective layer is formed on the back, a low retroreflective performance can be obtained even if a resin is coated on the surface side, and the first time using a high refractive index glass sphere with a refractive index of 2.0 or more Relatively high reflection performance can be obtained. However, the retroreflective performance of the reflective material obtained by this method does not reach the very high reflective performance possessed by ordinary open-type retroreflective materials. In addition, in order to improve the washability, it is necessary to increase the thickness of the resin covering the surface of the glass sphere as much as possible, and there is a problem that a material having high reflection performance cannot be obtained.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and has a high retroreflective performance, a small decrease in the retroreflective performance due to washing and dry cleaning, and excellent washing resistance. It is an object of the present invention to provide a highly durable retroreflective material.

[0008]

The present inventors have made intensive studies on the development of such a reflective material. As a result, when the surface of the transparent microsphere is covered with resin, the focus of light shifts from the rear surface of the transparent microsphere. Although the retroreflective performance is reduced, it has been found that by providing a resin layer on the back surface of the transparent microsphere, the deviation can be corrected and good retroreflective performance can be obtained, and the present invention has been reached.

That is, a layer of transparent microspheres, a fixed resin layer for partially burying and holding the transparent microspheres, a reflective layer provided between the transparent microspheres and the fixed resin layer, A first transparent resin layer provided at a thickness of 20 μm or less between the microspheres and the reflective layer, and a second transparent resin layer coated on the side of the transparent microspheres exposed to the air; A retroreflective material wherein the thickness of the second transparent resin layer is 0.005 to 20 μm at the top of the transparent microsphere, and is formed in a concentric ellipse so as to cover the exposed surface of the transparent microsphere. It is about.

Hereinafter, the present invention will be described in detail. A first example of the retroreflective material of the present invention will be described with reference to FIG. In FIG. 1, a first transparent resin layer 2 is formed behind a transparent microsphere 1, and a reflective layer 3 formed by aluminum evaporation or the like is provided behind the first transparent resin layer 2. Then, they are held by the fixing resin layer 4 so that a part of them is buried. The fixing resin layer 4 is directly held on the fiber cloth 5. Further, a second transparent resin layer 6 is provided on the exposed surface of the transparent microsphere 1 in the air. The second transparent resin layer 6 is a thin film of 0.005 to 20 μm at the top of the transparent microsphere 1 and is formed in a concentric ellipse so as to cover the exposed surface of the transparent microsphere 1.

Here, the transparent microspheres 1 have an average particle diameter of 500 μm.
m, preferably 30 to 200 μm. When the average particle diameter exceeds 500 μm, the thickness of the retroreflective material becomes large, the flexibility is lost, and a versatile light reflective material cannot be obtained. The refractive index of the transparent microsphere 1 is 1.80.
~ 2.00 is preferred. More preferably, 1.90-
1.96. Refractive index less than 1.80 or 2.0
If it exceeds 0, the focal position of the incident light will not be aligned with the reflective layer, and the retroreflective performance will deteriorate, which is not preferable.

Any material may be used as the material of the transparent microspheres 1 as long as it has high transparency and the refractive index is within the above-mentioned range. It is also excellent in washability, chemical resistance and weather resistance, and is preferable.

As the first transparent resin layer 2 provided behind the transparent microspheres 1, for example, various synthetic resins such as a polyurethane resin, a polyester resin, an acrylic resin or a reaction product or mixture thereof can be used. However, a colorless or colored resin having high transparency is preferable. If the transparency is reduced, the retroreflection performance is also significantly reduced, which is not preferable. Further, those having high washing resistance are preferable, chemical resistance to alkaline detergents and acidic neutralizing agents, etc., solvent resistance to various organic solvents such as trichloroethane and perchloroethane in dry cleaning, durability to high-temperature hot water, or As a combination thereof, a resin having a high concentration of a strong alkaline detergent and having excellent washing durability at high temperatures is desirable. In addition, a suitable amount of a cross-linking agent such as a polyisocyanate cross-linking agent, a melamine cross-linking agent, or an epoxy cross-linking agent is blended for the purpose of improving the adhesion holding property to the transparent microspheres, the adhesion to the reflective layer, and the washing resistance. However, it is also preferable to carry out a crosslinking reaction of the transparent resin. The first transparent resin layer 2 may use the same resin as the second transparent resin layer 6 that covers the surface of the transparent microsphere 1, or may use a different resin.

It is also preferable to add a silane coupling agent. By compounding a silane coupling agent,
The adhesion between the first transparent resin layer 2 and the metal thin film forming the reflection layer 3 is improved, and the washability is improved. Further, it is also preferable to use a resin obtained by adding a silane coupling agent to all or a part of the resin used for the first transparent resin layer 2.

Further, a coloring material may be mixed with the first transparent resin layer 2 to form a colored reflecting material. This first
The thickness of the transparent resin layer 2 is preferably 20 μm or less, more preferably 1 to 10 μm. If the layer thickness is less than 1 μm, the washing resistance effect of the transparent microspheres 1 is poor, and if it exceeds 20 μm, there is a problem that light is not focused on the reflective layer 3 and the retroreflective performance is reduced.

The reflective layer 3 provided on the back surface of the transparent microsphere 1 of the present invention is made of aluminum, gold, silver, tin, nickel,
A thin metal film such as stainless steel is formed by vapor deposition, sputtering or plating. Alternatively, a transparent metal film made of an oxide film of aluminum, titanium, silica, or the like, or a transparent metal film of zinc sulfide or the like can be formed by vapor deposition, sputtering, or the like. Further, a multilayer reflective layer can be formed by a combination of the above metal films. In particular, an aluminum thin film which is inexpensive and has high light reflectance is preferably used.

As the fixing resin layer 4 used in the present invention, for example, an acrylic resin, a polyurethane resin, a polyester resin, an epoxy resin, a nylon resin,
Various synthetic resins such as a rubber-based resin and a vinyl-based resin can be used. Further, two or more kinds of reactants or mixtures thereof can also be used. Strongly adheres to the transparent microspheres 1 or the reflective layer 3 formed on the back surface thereof, has a strong force of holding the transparent microspheres 1 and has a strong adhesiveness to a fiber cloth, and has a detergent and a neutralizing agent during washing. Desirable are those that are hardly affected by the chemicals and those that have high durability against physical actions such as rubbing and friction. Further, an optimum resin can be appropriately selected from the viewpoint of flexibility and the like depending on the application. In particular, polyester resin and polyurethane resin,
Alternatively, such a mixture is preferable because a composition having a strong adhesiveness to a metal thin film as a reflective layer, a soft composition, and a strong washing resistance can be easily selected.

A suitable amount of a polyisocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a melamine-based crosslinking agent, etc. is blended to improve the washing resistance and the physical durability of the fixing resin layer 4, and the fixing resin is cross-linked and solidified. Are also preferably used. In addition, a silane coupling agent, titanium oxide,
It is also preferable to appropriately mix inorganic fillers such as carbon black, aluminum powder, and silica powder as a reinforcing material to increase durability. In particular, the silane coupling agent is preferable because the adhesion to the metal thin film as the reflective layer is improved, and the erosion of the metal thin film by a detergent or a neutralizing agent during washing can be protected.

The burying rate of the transparent microspheres 1 in the fixed resin layer 4 is 40 to 80% of the diameter of the microspheres, and about 50% is most preferable from the viewpoint of the retention and reflection performance of the transparent microspheres 1. . If the burial ratio is less than 40%, the fixation of the transparent microspheres 1 becomes poor, the transparent microspheres 1 tend to fall off, and the washing resistance and the like tend to be reduced. On the other hand, if it exceeds 80%, the reflective performance is reduced when a transparent resin layer is coated thereon, and the reflective performance is extremely reduced particularly at a high incident angle.

The fiber cloth 5 used in the present invention includes:
Polyester fiber, polyamide fiber, polyacrylonitrile fiber, vinylon fiber, rayon fiber and cotton.
A woven fabric, a knitted fabric, a nonwoven fabric, and the like formed from natural fibers such as silk and wool or a blend fiber thereof.

As the second transparent resin layer 6 coated on the surface of the transparent microsphere 1 used in the present invention, for example, an acrylic resin, a polyurethane resin, a polyester resin, a fluorine resin, a vinyl resin, Various synthetic resins such as a rubber-based resin or a reaction product or mixture thereof can be used. In particular, it has high transparency, small light transmission loss, and strong adhesion to the transparent microspheres, and is hardly peeled off at the interface with the transparent microspheres 1 in washing, and hardly deteriorated by a chemical used for washing. Compositions are preferred. In particular, polyester-based resins, fluorine-based resins, urethane-based resins, polyester-urethane-based resins, rubber-based resins, and the like are preferable.

A suitable amount of a polyisocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a melamine-based crosslinking agent, or the like is blended in the second transparent resin layer 6 to crosslink and solidify the transparent resin, thereby significantly improving the washing resistance. Can be. It is also preferable to mix an appropriate amount of a silane coupling agent because the adhesion to the transparent microspheres 1 is improved. Further, it is preferable to use a resin obtained by adding a silane coupling agent to all or a part of the resin used for the second transparent resin layer 6.

Also, by blending a coloring material, various new colored reflecting materials can be obtained. Second transparent resin layer 6
Is such that the layer thickness at the top of the transparent microsphere 1 is 0.0
It is from 05 μm to 20 μm. Preferably it is 2 to 10 μm. If the layer thickness is less than 0.005 μm, the effect of improving the washing resistance is poor, and if it is 20 μm or more, the reflection performance is undesirably reduced. In the case where a colored reflective material is manufactured using a transparent resin containing a coloring material, a thicker transparent resin layer can provide a beautiful colored material.

The open type retroreflective material according to the present invention is manufactured, for example, by the following method. A resin layer for temporary embedding of microspheres having a low softening point, such as polyethylene film, is laminated on a film substrate such as a polyethylene terephthalate film to prepare a temporary embedding support. The temporary buried support is heated at a temperature equal to or higher than the softening point of the resin for temporary burying of microspheres, and transparent microspheres are scattered over the entire surface in a single layer, and 20 to 60% of the diameter of the microspheres is temporarily used. It is buried in the burying resin layer. A thin transparent first resin layer is formed on the transparent microspheres by coating the dilute solution of the transparent resin on the microsphere exposed surface of the temporary buried support of the microspheres thus formed and drying. I do. A reflection layer is formed on the resin layer by metal deposition or the like. Furthermore, after a fixing resin layer is laminated thereon to a predetermined thickness, the fixing resin layer is adhered to the fiber cloth with the fixing resin alone or via an adhesive. Next, the temporary buried support in which the transparent microspheres are temporarily embedded is peeled off to obtain an open-type retroreflective material in which a part of the microspheres is exposed to the air. Next, a transparent resin thin film is coated on the surface side of the transparent microspheres of the retroreflective material, and dried to form a second transparent resin layer having a predetermined thickness. Wood is obtained.

Here, as the temporary burying support for temporarily burying the transparent microspheres, polyester film such as polyethylene terephthalate and polyethylene naphthalate which are stable at high temperature, paper and the like are preferably used for the film substrate. Further, as a resin layer for embedding microspheres for embedding microspheres, a resin layer having a lower softening temperature than the film substrate is required, and a polyethylene film layer, a polypropylene film layer, an acrylic pressure-sensitive adhesive layer, and a polyurethane pressure-sensitive adhesive layer are required. ,
A polyester adhesive layer or the like is preferably used.

As a second example according to the present invention, as shown in FIG. 2, in order to increase the adhesiveness between the fixing resin layer 4 and the fiber cloth 5, it is possible to bond the adhesive resin layer 4 with an adhesive 7 therebetween. . As the adhesive, conventionally known acrylic adhesives, vinyl adhesives, polyurethane adhesives, polyester adhesives, polyamide adhesives, rubber adhesives and the like are used. It is necessary to select an optimum adhesive depending on the type of the fixing resin and the fiber cloth, but generally, a polyester-based adhesive or a polyurethane-based adhesive is preferably used. In order to improve the durability of the adhesive, an appropriate amount of a polyisocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a melamine-based crosslinking agent, or the like is blended, and the adhesive is crosslinked and solidified, whereby the washing resistance can be improved.

As a third example according to the present invention, as shown in FIG. 3, a hot melt adhesive layer 8 held by release paper 9 can be laminated on the fixing resin layer 4. As the hot melt adhesive, conventionally known polyurethane adhesives, polyester adhesives, polyamide adhesives and the like are used. Further, the fixing resin layer 4 and the hot melt adhesive layer 8 can be bonded together with an adhesive.

The retroreflective material provided with the hot-melt adhesive layer 8 melts the hot-melt adhesive with heat and can be directly bonded to a fiber cloth or the like.

[0029]

According to the retroreflective material of the present invention, a first transparent resin layer is formed on the back surface of a transparent microsphere, and a reflective layer composed of a metal thin film is formed. Next, a second transparent resin layer is formed on the surface of the transparent microsphere to provide an open-type retroreflective material having excellent washing performance and high reflection performance. Further, the retroreflective material of the present invention, when the surface of the transparent microspheres is covered with a resin layer, the focus of light is shifted from the back surface of the transparent microspheres and the retroreflective performance is reduced, but another resin is provided on the back surface of the transparent microspheres. By disposing the layer, the deviation can be corrected, and good retroreflective performance can be obtained.

[0030]

Embodiments of the present invention will be described below with reference to embodiments. Embodiment 1 A temporary buried film obtained by laminating a polyethylene film having a thickness of 40 μm on a polyethylene terephthalate film having a thickness of 75 μm is heated at 120 ° C. for 3 minutes to melt the polyethylene film, and an average particle diameter of 80 μm is formed thereon.
A medium refractive index glass microsphere having a refractive index of 1.92 μm and a refractive index of 1.92 is sprayed on a single layer almost entirely, and approximately 50% of the diameter of the glass microsphere is temporarily embedded.

A transparent resin intermediate layer made of a polyurethane resin is formed thereon to a thickness of 5 μm, and a thickness of about 8 μm is formed thereon.
A reflective layer of a thin aluminum film having a thickness of 00 ° is formed by vacuum evaporation, and a fixing resin layer composed of 40 parts by mass of a polyester resin and 5 parts by mass of coronate HL is further formed thereon with a thickness of approximately 6
It is formed so as to have a thickness of 0 μm, and is adhesively fixed to a polyester-cotton taffeta (65/35 blend) woven fabric having a basis weight of about 103 g / m ² . Next, the temporary buried film in which the glass microspheres are temporarily embedded is peeled off to obtain an open type retroreflective material in which about 50% of the glass microspheres are exposed to the air. Then, a polyester resin 50 is applied to the surface of the glass microsphere.
A second transparent resin layer consisting of parts by mass and 4 parts by mass of Coronate HL is formed in a concentric ellipse so as to cover the exposed surface of the glass microspheres with a thickness of 7 μm to obtain a retroreflective material.

This retroreflective material is referred to as ISO 6330-1A.
After repeating the washing 10 times under the conditions according to the method (washing temperature 92 ° C.), the reflection performance was measured. Here, the reflection performance was measured according to JIS Z 9117 "Reflection sheet and tape for security". Table 1 shows the results.

Embodiment 2 In the same manner as in Embodiment 1, a retroreflective material is prepared by using 1.5 parts by mass of aminosilane as a silane coupling agent in the second transparent resin layer. did. The retroreflective material was subjected to a washing test in the same manner as in Embodiment 1, and the reflection performance was measured. The results are shown in Table 1.

Comparative Example 1 A method similar to that of the first embodiment, except that the open type retroreflective material without the second transparent resin layer was subjected to a washing test as in the first embodiment, and the reflection performance was measured. The results are shown in Table 1.

COMPARATIVE EXAMPLE 2 A method similar to that of the first embodiment is used, except that the first transparent resin layer is not formed, and a retroreflective material having only the second transparent resin layer is formed. A washing test was performed in the same manner as in Embodiment 1, the reflection performance was measured, and the results are shown in Table 1.

[Table 1]

Embodiment 3 A temporarily immersed film obtained by laminating a polyethylene film having a thickness of 40 μm on a polyethylene terephthalate film having a thickness of 75 μm is heated at 120 ° C. for 3 minutes to melt the polyethylene film. 8
0 μm, medium refractive index glass microspheres with a refractive index of 1.92 are scattered in a single layer almost over the entire surface, and about 40% of the diameter of the glass microspheres
Is temporarily buried.

A colorless first transparent resin layer made of a polyurethane resin is formed thereon to a thickness of 6 μm. A reflective layer of an aluminum thin film having a thickness of about 800 ° is formed thereon by vacuum evaporation, and a fixing resin layer comprising 50 parts by weight of a polyester-urethane resin and 2 parts by weight of hexamethylene diisocyanate is further formed thereon to a thickness of about 60 μm. Then, a polyester hot melt adhesive having a thickness of 75 μm is attached. Next, the temporary buried film in which the glass microspheres are temporarily embedded is peeled off to obtain an open-type retroreflective material in which about 40% of the glass microspheres are exposed to the air. Next, 50 parts by mass of a polyester-based adhesive, 2.5 parts by mass of hexamethylene diisocyanate, and 1.5 parts by weight of an aminosilane coupling agent were added to the surface of the glass microspheres.
A second transparent resin layer composed of parts by mass is formed in a concentric ellipse shape so as to cover the exposed surface of the glass microspheres with a thickness of 4 μm to obtain a retroreflective material.

The retroreflective material was made of polyester-cotton (6
5/35 blend) The fabric was adhered to the fabric at a temperature of 150 ° C. and a pressure of 40 kPa for 3 minutes to prepare a fabric base fabric to which a retroreflective material was attached, and the fabric was washed under the same washing conditions as in the first embodiment. The reflection performance was measured. Table 2 shows the results.

Embodiment 4 An ink composed of 100 parts by mass of a one-component urethane screen ink, 20 parts by mass of a red pigment, and 10 parts by mass of methyl ethyl ketone on the surface of glass microspheres of an open type retroreflective material prepared in Embodiment 3. And dried to form a red resin layer having a thickness of 9 μm as a second transparent resin layer to obtain a red retroreflective material. This red retroreflective material exhibited a good red color in reflection.

The retroreflective material was made of polyester-cotton (6
5/35 blend) The fabric was adhered to the fabric at a temperature of 150 ° C. and a pressure of 40 kPa for 3 minutes to prepare a fabric base fabric to which a retroreflective material was attached, and the fabric was washed under the same washing conditions as in the first embodiment. The reflection performance was measured. Table 2 shows the results.

[Table 2]

[0041]

As described above, according to the present invention, a first transparent resin layer is formed on the back surface of a transparent microsphere, a reflection layer composed of a metal thin film is formed, and the transparent microsphere is further formed. By forming the second transparent resin layer on the surface, it is possible to provide an open-type retroreflective material having excellent washing performance and high reflective performance. Further, the retroreflective material of the present invention, when the surface of the transparent microspheres is covered with a resin layer, the focus of light is shifted from the back surface of the transparent microspheres, and the retroreflective performance is reduced.
By disposing another resin layer on the back surface of the transparent microsphere, the deviation can be corrected, and good retroreflection performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a first example of a retroreflective material according to the present invention.

FIG. 2 is a cross-sectional view illustrating a second example of a retroreflective material according to the present invention.

FIG. 3 is a cross-sectional view illustrating a third example of a retroreflective material according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent microsphere 2 First transparent resin layer 3 Reflective layer 4 Fixed resin layer 5 Fiber cloth 6 Second transparent resin layer 7 Adhesive layer 8 Hot melt adhesive layer 9 Release paper

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shozo Fukase 2-6-1-1, Ogawa, Chiyogawa-cho, Kameoka, Kyoto Prefecture Inside Unitikas Park Light Co., Ltd. (72) Daisuke Ota 2--16, Ogawa, Chiyogawa-cho, Kameoka, Kyoto -1 Inside Unitikas Park Light Co., Ltd. (72) Inventor Takumi Ii 2-2-1 Ogawa, Chiyokawa-cho, Kameoka, Kyoto Prefecture Inside Unitikas Park Light Co., Ltd. (72) Daisuke Minoura 2-16, Ogawa, Chiyogawa-cho, Kameoka, Kyoto -1 F-term in Unitikas Sparklight Co., Ltd. (Reference) 2H042 EA07 EA12 EA22 4F100 AB10 AG00 AK01A AK01B AK41 BA10A BA10C CB03 DD32A DE01A DG11C GB72 JL10A JN01A JN06 JN06A

Claims (7)

[Claims] 1. A layer of transparent microspheres, a fixed resin layer for partially burying and holding the transparent microspheres, a reflective layer provided between the transparent microspheres and the fixed resin layer, A first layer having a thickness of 20 μm or less between the microsphere and the reflective layer;
And a second transparent resin layer coated on the side of the transparent microsphere exposed to air, wherein the thickness of the second transparent resin layer is 0.005 at the top of the transparent microsphere. ~
A retroreflective material having a thickness of 20 μm and formed in a concentric elliptical shape so as to cover an exposed surface of a transparent microsphere. 2. A silane coupling agent and / or a resin obtained by adding a silane coupling agent to a second transparent resin layer covering the transparent microspheres.
The retroreflective material described. 3. The retroreflective material according to claim 1, wherein a coloring material is blended in the second transparent resin layer that covers the transparent microspheres. 4. The retroreflective material according to claim 1, wherein the fixing resin layer is directly bonded to the fiber cloth. 5. The retroreflective material according to claim 1, wherein the fixing resin layer is bonded to the fiber cloth via an adhesive. 6. The retroreflective material according to claim 1, wherein the fixing resin layer is directly bonded to the hot melt adhesive. 7. The retroreflective material according to claim 1, wherein the fixing resin layer is bonded to the hot melt adhesive via an adhesive.