JP3221771B2 - Cube corner type retroreflective sheet - Google Patents
Cube corner type retroreflective sheetInfo
- Publication number
- JP3221771B2 JP3221771B2 JP16504093A JP16504093A JP3221771B2 JP 3221771 B2 JP3221771 B2 JP 3221771B2 JP 16504093 A JP16504093 A JP 16504093A JP 16504093 A JP16504093 A JP 16504093A JP 3221771 B2 JP3221771 B2 JP 3221771B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- layer
- refractive index
- transmitting layer
- retroreflective
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Description
【０００１】[0001]
【産業上の利用分野】本発明は、道路標識、工事標識、
自動車、オートバイ等の車輌のナンバープレート、衣
服、救命具等の安全用資材、看板等のマーキング等にお
いて有用な再帰反射シートに関する。BACKGROUND OF THE INVENTION The present invention relates to a road sign, a construction sign,
The present invention relates to a retroreflective sheet useful as a license plate for vehicles such as automobiles and motorcycles, clothing, safety materials such as lifesaving devices, and markings for signboards and the like.
【０００２】[0002]
【従来の技術】従来より光を光源に向けて再帰反射させ
る再帰反射シートはよく知られており、その再帰反射性
を利用して、該シートは、道路標識、工事標識、車輌の
ナンバープレート、安全用資材、看板などのディスプレ
イマーキング等の分野で広く利用されている。2. Description of the Related Art Conventionally, a retroreflective sheet for retroreflecting light toward a light source is well known. By utilizing the retroreflectivity, the sheet can be used as a road sign, a construction sign, a vehicle license plate, a vehicle license plate, or the like. It is widely used in fields such as safety materials and display marking of signboards.
【０００３】再帰反射シートはその再帰反射性を得るた
めの原理の相異により概ね３種に大別される。[0003] Retroreflective sheets are roughly classified into three types according to the difference in principle for obtaining the retroreflective properties.
【０００４】１つは、例えば、特公昭48-28837号公報、
特公昭61-13561号公報第３図等に記載されるような、ガ
ラスビーズのごとき透明微小球をレンズとして用い、そ
のレンズのちょうど焦点位置付近にアルミニウムで代表
されるような金属蒸着膜のごとき金属光反射層を配置し
た一般レンズ型と呼ばれる再帰反射シートである。[0004] One is, for example, Japanese Patent Publication No. 48-28837,
As shown in FIG. 3 of JP-B-61-13561, a transparent microsphere such as a glass bead is used as a lens, and a metal vapor-deposited film represented by aluminum is located near the focal point of the lens. This is a retroreflective sheet called a general lens type in which a metal light reflecting layer is arranged.
【０００５】また１つは、特公昭61-13561号公報第６図
に記載されるような、幾何学的に再帰反射条件を満たす
一般にキューブコーナーと呼ばれる透明成型物を利用
し、その成型物の背面にカプセル状に空気のごとき低屈
折率気体をとじ込め、高屈折率の樹脂状物と低屈折率気
体の屈折率の差を利用して両者の界面にて光を全反射さ
せる一般にカプセルキューブコーナー型と呼ばれる再帰
反射シートである。[0005] One is to use a transparent molding generally called a cube corner which geometrically satisfies the retroreflection condition as shown in FIG. 6 of JP-B-61-13561, and Capsule cube in which low-refractive-index gas such as air is trapped in a capsule shape on the back side, and light is totally reflected at the interface between the high-refractive-index resin and the low-refractive-index gas using the refractive index difference between the two. This is a retroreflective sheet called a corner type.
【０００６】さらにもう１つは上記同様キューブコーナ
ー透明成型物を利用し、その成型物の背面にアルミニウ
ムで代表されるような金属蒸着膜のごとき金属光反射層
を積層配置した一般にメタライズドキューブコーナー型
と呼ばれる再帰反射シートである。Another one is a metallized cube corner type in which a cube corner transparent molded product is used similarly to the above, and a metal light reflecting layer such as a metal vapor deposition film represented by aluminum is laminated on the rear surface of the molded product. It is a retroreflective sheet called "."
【０００７】いずれにしろ、これら再帰反射シートは、
その光の反射においける再帰性（光が光源に向けてもど
る性質）を得るための透明球状レンズ、あるいはキュー
ブコーナー型透明成型物等の再帰反射性要素と、光を反
射させるための金属蒸着膜のごとき金属層、あるいは低
屈折率気体／高屈折率樹脂界面のごとき光全反射界面等
の光反射層よりなっている。In any case, these retroreflective sheets are:
A retro-reflective element such as a transparent spherical lens or a cube-corner type transparent molding to obtain the reflexivity (property of returning the light to the light source) in the reflection of the light, and a metal deposition to reflect the light It is composed of a metal layer such as a film, or a light reflection layer such as a light total reflection interface such as a low refractive index gas / high refractive index resin interface.
【０００８】[0008]
【発明が解決しようとする課題】しかしながら、これら
従来の再帰反射シートにおいては、種々問題点がある。However, these conventional retroreflective sheets have various problems.
【０００９】まず、金属蒸着膜のごとき金属光反射層を
用いた再帰反射シートにおいては、光の反射効率が悪
く、また、金属特有の金属色のため再帰反射シートの色
相にくすみを生じ、白度の高い再帰反射シートが得られ
ないという問題点である。First, in a retroreflective sheet using a metal light reflective layer such as a metal vapor deposition film, the light reflection efficiency is poor, and because of the metal color peculiar to metal, the hue of the retroreflective sheet becomes dull and white. There is a problem that a high retroreflection sheet cannot be obtained.
【００１０】また、低屈折率気体／高屈折率樹脂界面の
ごとき光全反射界面光反射層を用いた再帰反射シートに
おいては、光の反射効率もよく金属色に基づくような色
相のくすみも発生しないが、低屈折率気体を高屈折率樹
脂界面に封じ込めるための煩雑なカプセリング工程を必
要とし、その生産性が悪いという問題点がある。Further, in a retroreflective sheet using a light-reflective interface light reflection layer such as a low-refractive-index gas / high-refractive-index resin interface, the light reflection efficiency is good and a hue dullness based on a metallic color also occurs. However, there is a problem that a complicated encapsulation process for sealing the low refractive index gas at the high refractive index resin interface is required, and the productivity is low.
【００１１】加えて、シートのカッティング、あるいは
外的要因でのシートのクラック等により低屈折率気体を
封じ込めたカプセルが破壊された場合は、カプセル中へ
の水等の侵入により光全反射条件が損なわれ、光の反射
性能が低下してしまうという問題もある。In addition, when the capsule containing the low-refractive-index gas is broken due to sheet cutting or sheet cracking due to an external factor, the condition of total light reflection is caused by the penetration of water or the like into the capsule. There is also a problem that the light reflection performance is deteriorated.
【００１２】本発明の目的は、これら従来型再帰反射シ
ートの問題点に鑑み、色相にくすみが生じることなく、
また、煩雑なカプセリング工程が不要で、カプセル破壊
の心配も全くない、優れた再帰反射シートを提供するこ
とにある。SUMMARY OF THE INVENTION In view of the problems of the conventional retroreflective sheeting, an object of the present invention is to provide a color filter without dulling the hue.
Another object of the present invention is to provide an excellent retroreflective sheeting that does not require a complicated encapsulation step and does not cause any capsule destruction.
【００１３】本発明者等は、種々構成の光反射層につい
て検討した結果、高屈折率光透過層と低屈折率層を用い
ることにより、両者の界面で光が効率よく全反射するこ
とを見い出し、上記課題を解決し得ることを知見した。The present inventors have studied various types of light-reflecting layers, and have found that by using a high-refractive-index light-transmitting layer and a low-refractive-index layer, light is efficiently totally reflected at an interface between the two layers. It has been found that the above problems can be solved.
【００１４】[0014]
【課題を解決するための手段】かくして本発明によれ
ば、キューブコーナー型再帰反射性要素を含む光透過性
層と、その背面に積層形成された高屈折率光透過層と、
さらにその背面に積層された低屈折率層とからなるキュ
ーブーコーナー型再帰反射シートにおいて、該高屈折率
光透過層が硫化亜鉛、二酸化チタン、酸化鉛から選ばれ
る薄層であり、該高屈折率光透過層が直接再帰性反射要
素に積層され、該低屈折率層が接着剤樹脂層であり、該
低屈折率層が直接高屈折率光透過層に積層されているこ
とを特徴とするキューブコーナー型再帰反射シートが提
供される。Thus, according to the present invention, there is provided a light-transmitting layer including a cube-corner retroreflective element, a high-refractive-index light-transmitting layer laminated on the back surface thereof,
Further, in the cube-corner type retroreflective sheet comprising a low refractive index layer laminated on the back surface thereof, the high refractive index light transmitting layer is a thin layer selected from zinc sulfide, titanium dioxide, and lead oxide. The low refractive index layer is an adhesive resin layer, and the low refractive index layer is directly laminated on the high refractive index light transmitting layer. A cube-corner retroreflective sheet is provided.
【００１５】本発明の再帰反射シートの最大の特徴は、
再帰反射性要素を通過してきた光を、高屈折率光透過層
と低屈折率層界面で全反射させることにあり、即ち、カ
プセリングが必要となる空気等のごとき低屈折率気体を
用いずに全反射を達成したことにある。The most significant feature of the retroreflective sheeting of the present invention is that
Light that has passed through the retroreflective element is totally reflected at the interface between the high-refractive-index light-transmitting layer and the low-refractive-index layer, that is, without using a low-refractive-index gas such as air that requires encapsulation. It has achieved total reflection.
【００１６】本発明において、高屈折率光透過層／低屈
折率層界面の上部に位置する再帰反射性要素を含む光透
過性層及び高屈折率光透過層は共に光透過性でなくては
ならない。In the present invention, both the light-transmitting layer including the retroreflective element and the high-refractive-index light-transmitting layer located above the interface between the high-refractive-index light-transmitting layer and the low-refractive-index layer must be light-transmitting. No.
【００１７】再帰反射性要素を含む光透過性層は、再帰
反射性をシートに付与できる機能を有し、光非透過性の
金属蒸着膜を含まないものであればよいが、再帰反射性
能が高く、また、全反射条件を形成しやすいキューブコ
ーナー型再帰反射性要素を用いることが最も好ましい。The light-transmitting layer containing a retroreflective element has a function of imparting retroreflective properties to the sheet, and may be any layer that does not include a light-impermeable metal deposited film. It is most preferable to use a cube-corner retroreflective element that is high and easily forms a total reflection condition.
【００１８】再帰反射性要素を含む光透過性層は、より
高い再帰反射性能を得るためにはより高い光透過性が必
要であり、通常、全光透過率30％以上、好ましくは50％
以上、より好ましくは60％以上に調整するのがよい。A light-transmitting layer containing a retroreflective element requires higher light transmittance in order to obtain higher retroreflective performance, and usually has a total light transmittance of 30% or more, preferably 50%.
The above is more preferable, and it is better to adjust it to 60% or more.
【００１９】キューブコーナー型再帰反射性要素を形成
するには、例えば透明合成樹脂シートに、凹型キューブ
コーナー型要素を持つエンボスロールでエンボス加工す
ることにより、シートの片面の全面に亘って多数の凸型
キューブコーナー型再帰反射性要素を形成する等の手段
が好適に採用できる。In order to form a cube-corner retroreflective element, for example, a transparent synthetic resin sheet is embossed with an embossing roll having a concave cube-corner element, so that a large number of convex portions are formed on one surface of the sheet. Means such as forming a cube-corner retroreflective element can be suitably employed.
【００２０】上記再帰反射性要素を含む光透過性層に
は、通常、透明合成樹脂が用いられる。このような透明
合成樹脂としては、特に限定されるものではなく、例え
ばアクリル系樹脂、ウレタン系樹脂、フッ素系樹脂、ポ
リエステル系樹脂、塩化ビニル系樹脂、ポリカーボネー
ト系樹脂、ポリアリレート系樹脂、シリコン系樹脂、ポ
リオレフィン系樹脂、アイオノマー樹脂等が単独で、も
しくは、混合されて用いられ中でも透明性、耐候性等に
優れるアクリル系樹脂、ウレタン系樹脂、フッ素系樹
脂、ポリカーボネート系樹脂等が好ましく用いられる。A transparent synthetic resin is usually used for the light-transmitting layer containing the retroreflective element. Such a transparent synthetic resin is not particularly limited, for example, acrylic resin, urethane resin, fluorine resin, polyester resin, vinyl chloride resin, polycarbonate resin, polyarylate resin, silicon resin A resin, a polyolefin resin, an ionomer resin, or the like is used alone or as a mixture, and among them, an acrylic resin, a urethane resin, a fluorine resin, a polycarbonate resin, or the like having excellent transparency and weather resistance is preferably used.
【００２１】再帰反射性要素を含む光透過性層は、光透
過性を著しく損なわない範囲で、顔料、染料等の着色剤
にて着色してもよく、また紫外線吸収剤、光安定剤、熱
安定剤等の各種添加剤を含んでもよい。The light-transmitting layer containing the retroreflective element may be colored with a coloring agent such as a pigment or a dye as long as the light-transmitting property is not significantly impaired. Various additives such as a stabilizer may be included.
【００２２】本発明において再帰反射性要素を含む光透
過性層の背面には高屈折率光透過層が積層される。In the present invention, a high refractive index light transmitting layer is laminated on the back surface of the light transmitting layer including the retroreflective element.
【００２３】高屈折率光透過層の光透過性についても、
より高い再帰反射性能を得るためには、より高い光透過
性が必要で、通常、全光線透過率50％以上、好ましくは
60％以上、より好ましくは80％以上に調整される。Regarding the light transmittance of the high refractive index light transmitting layer,
In order to obtain higher retroreflection performance, higher light transmittance is required, and usually, the total light transmittance is 50% or more, preferably
It is adjusted to at least 60%, more preferably at least 80%.
【００２４】高屈折率光透過層に用いる構成物の屈折率
n1については、通常、屈折率1.8以上、好ましくは2.0以
上、より好ましくは2.2以上に設定すればよい。Refractive index of components used for high refractive index light transmitting layer
n1 is usually set to a refractive index of 1.8 or more, preferably 2.0 or more, and more preferably 2.2 or more.
【００２５】また高屈折率光透過層の屈折率n1と、該高
屈折率光透過層の背面に積層された低屈折率層の屈折率
n2との比n1／n2は、1.42以上となるように、それぞれ高
屈折率光透過層の構成物及び低屈折率層の構成物が選定
されるのが好ましい。該比n1／n2が1.42以上であれば、
高屈折率光透過層、低屈折率層界面における全反射性が
得やすいので好ましい。該比n1／n2は、１.50以上であ
るのがより好ましく、1.60以上であるのがさらに好まし
い。The refractive index n 1 of the high refractive index light transmitting layer and the refractive index of the low refractive index layer laminated on the back surface of the high refractive index light transmitting layer
The ratio n 1 / n 2 with n 2, as a 1.42 or more, preferably constituents of the respective constituents of the high refractive index light-transmitting layer and a low refractive index layer is selected. If the ratio n 1 / n 2 is 1.42 or more,
This is preferable because total reflection at the interface between the high refractive index light transmitting layer and the low refractive index layer is easily obtained. The ratio n 1 / n 2 is more preferably 1.50 or more, and even more preferably 1.60 or more.
【００２６】高屈折率光透過層に用いられる構成物とし
ては、上記光透過性及び屈折率条件を満足するものなら
なんでもよいが、通常硫化亜鉛、二酸化チタン、酸化鉛
等の無機物が好ましく用いられる。As the component used for the high refractive index light transmitting layer, any material can be used as long as it satisfies the above-mentioned conditions of light transmittance and refractive index. In general, inorganic materials such as zinc sulfide, titanium dioxide and lead oxide are preferably used. .
【００２７】高屈折率光透過層を形成するには、特に限
定されるものではないが真空蒸着法、スパッタリング
法、イオンプレーティング法等を用いて簡単に形成する
ことができる。The high-refractive-index light-transmitting layer can be easily formed by, for example, but not limited to, a vacuum deposition method, a sputtering method, or an ion plating method.
【００２８】高屈折率光透過層の厚みは通常0.005〜1.0
μm、好ましくは0.05〜0.5μm、さらに好ましくは0.08
〜0.3μmとされる。The thickness of the high refractive index light transmitting layer is usually 0.005 to 1.0.
μm, preferably 0.05 to 0.5 μm, more preferably 0.08
0.30.3 μm.
【００２９】高屈折率光透過層の背面に積層される低屈
折率層は、前述の屈折率条件を満足するような構成物を
用いた層であれば無機物、有機物等なんでもよいが、通
常屈折率1.7以下、好ましくは1.6以下、より好ましくは
1.5以下の屈折率を有する樹脂を用いて形成され、例え
ばアクリル系樹脂、シリコン系樹脂、ウレタン系樹脂、
ゴム系樹脂、エポキシ系樹脂、ポリエステル系樹脂等が
単独であるいは混合されて用いられる。The low refractive index layer laminated on the back surface of the high refractive index light transmitting layer may be any of inorganic and organic substances as long as it is a layer using a component satisfying the above-mentioned refractive index condition. Rate 1.7 or less, preferably 1.6 or less, more preferably
Formed using a resin having a refractive index of 1.5 or less, for example, acrylic resin, silicon resin, urethane resin,
A rubber-based resin, an epoxy-based resin, a polyester-based resin, or the like is used alone or as a mixture.
【００３０】低屈折率層には各種添加剤を含有させるこ
とができ、例えば着色剤、充填剤、紫外線吸収剤、蛍光
増白剤等が添加可能である。The low refractive index layer can contain various additives, for example, a colorant, a filler, an ultraviolet absorber, a fluorescent brightener and the like.
【００３１】本発明においては、低屈折率層の上部に
は、光非透過性層が存在しないので、再帰反射性要素を
含む光透過性層及び高屈折率光透過層を無色透明とし、
低屈折率層を白色とすることにより、白度の高い美麗な
反射シートを簡単に製造することができる。In the present invention, since the light non-transmitting layer does not exist above the low refractive index layer, the light transmitting layer including the retroreflective element and the high refractive index light transmitting layer are made colorless and transparent.
By making the low refractive index layer white, a beautiful reflection sheet having high whiteness can be easily manufactured.
【００３２】また、再帰反射性要素を含む光透過性層及
び／又は高屈折率光透過層に有彩色の着色を施し、低屈
折率層を白色とすることにより、或いは再帰反射性要素
を含む光透過性層及び／又は高屈折率光透過層を無色透
明ないしは有彩色とし低屈折率層を有彩色に着色するこ
と等により、彩度の高い美麗な再帰反射シートを簡単に
製造することができる。The light-transmitting layer containing the retroreflective element and / or the high-refractive-index light-transmitting layer may be colored with a chromatic color and the low-refractive-index layer may be white, or may contain the retroreflective element. By making the light-transmitting layer and / or the high-refractive-index light-transmitting layer colorless and transparent or a chromatic color and coloring the low-refractive-index layer to a chromatic color, it is possible to easily manufacture a beautiful retroreflective sheet with high chroma. it can.
【００３３】本発明においては、低屈折率層を接着剤層
として形成することもできる。通常、再帰反射シートは
感圧接着剤層、感熱接着剤層等を用いて被着体に貼り付
けて使用されることが多く、低屈折率層を接着剤層とし
て用いることにより、付加的に接着剤層を設ける煩雑さ
を避けることができ、効率的である。In the present invention, the low refractive index layer can be formed as an adhesive layer. Usually, a retroreflective sheet is often used by attaching it to an adherend using a pressure-sensitive adhesive layer, a heat-sensitive adhesive layer, or the like, and additionally using a low refractive index layer as an adhesive layer. The complexity of providing an adhesive layer can be avoided and the process is efficient.
【００３４】低屈折率層を接着剤層とする場合において
は、高屈折率光透過層の上に塗布乾燥して形成してもよ
いが、再帰反射性要素を含む光透過性層、高屈折率光透
過層の形状にできるだけ影響を与えないよう、予め剥離
紙等の基材上に塗布乾燥した低屈折率層を高屈折率光透
過層上に積層、貼り合わせる方法を用いることが好まし
い。When the low-refractive-index layer is used as an adhesive layer, it may be formed by coating and drying on the high-refractive-index light-transmitting layer. It is preferable to use a method of laminating and bonding a low-refractive-index layer, which has been previously coated and dried on a base material such as release paper, on the high-refractive-index light-transmitting layer so as not to affect the shape of the high-refractive-index transmitting layer as much as possible.
【００３５】[0035]
【実施例】以下、本発明の再帰反射シートを実施例に基
づいて具体的に説明する。なお、試験方法は全て以下に
従って実施した。DESCRIPTION OF THE PREFERRED EMBODIMENTS The retroreflective sheet of the present invention will be specifically described below based on embodiments. In addition, all the test methods were implemented according to the following.
【００３６】(1) 色相及び白度 JIS Z-9117に規定される色の測定法に従って色相を測定
し（光源としてＣ光源を用いた）、得られた値をＬ*、
ａ*、ｂ*表色系にて現わした。またＬ*値をもって白度
とした。(1) Hue and whiteness Hue was measured according to a color measurement method defined in JIS Z-9117 (using a C light source as a light source), and the obtained values were expressed as L * ,
It is expressed in a * and b * color system. The L * value was used as whiteness.
【００３７】(2) 反射性能 JIS Z-9117に規定される反射性能の測定に従って再帰反
射シートの反射性能を測定した。なお、角度条件は観測
角0.2゜、入射角５゜にて実施した。(2) Reflection Performance The reflection performance of the retroreflective sheet was measured according to the measurement of the reflection performance specified in JIS Z-9117. The angle conditions were an observation angle of 0.2 ° and an incident angle of 5 °.
【００３８】(3) 全光線透過率 試験機として「カラーアナライザー TC-1800MK2」〔商
品名；東京電色(株)製〕により試料の全光線透過率を測
定した。(3) Total light transmittance The total light transmittance of the sample was measured using "Color Analyzer TC-1800MK2" (trade name; manufactured by Tokyo Denshoku Co., Ltd.) as a tester.
【００３９】なお、光を透過させる方向により全光線透
過率が大きく変化する場合は、２方向の測定値の平均値
をもって、全光線透過率とした。When the total light transmittance greatly changes depending on the direction in which light is transmitted, the average value of the measured values in two directions is defined as the total light transmittance.
【００４０】また、高屈折率光透過層の全光線透過率に
ついては、再帰反射性要素を含む光透過性層と該高屈折
率光透過層との積層品の全光線透過率を求め、得られた
値を再帰反射性要素を含む光透過性層の全光線透過率で
除し求めた。As for the total light transmittance of the high refractive index light transmitting layer, the total light transmittance of the laminate of the light transmitting layer including the retroreflective element and the high refractive index light transmitting layer is obtained. The obtained value was divided by the total light transmittance of the light transmitting layer including the retroreflective element.
【００４１】(4) 水浸漬後の外観 再帰反射シートを10cm角にカットし、水中に浸漬した。
その後、シートを水中から取り出し、暗室で懐中電灯を
用い再帰反射条件下で外観を観察し以下評点に従って評
価した。(4) Appearance after immersion in water The retroreflective sheet was cut into a 10 cm square and immersed in water.
Thereafter, the sheet was taken out of the water, and its appearance was observed under retroreflective conditions using a flashlight in a dark room, and evaluated according to the following ratings.
【００４２】１・・・・全体が均一に光り、光らない部分が
ない。 ２・・・・エッジ部分にわずかに光らない部分がある。 ３・・・・光らない部分が多数ある。1... The whole shines uniformly, and there are no non-lighting parts. 2. There is a part that does not shine slightly at the edge part. 3. There are many parts that do not shine.
【００４３】実施例１ ポリメチルメタクリレートを主成分とする透明アクリル
フイルムを加熱エンボス加工して、一方の表面の全面に
一辺約200μm、高さ約90μmのキューブコーナー型突起
を有する厚み約200μmの再帰反射要素を含む光透過性層
を得た。本光透過性層の全光線透過率は77.5％であっ
た。Example 1 A transparent acrylic film containing polymethyl methacrylate as a main component was heated and embossed, and a recursive film having a thickness of about 200 μm having a cube-corner type projection having a side of about 200 μm and a height of about 90 μm on the entire surface of one surface. A light transmissive layer containing a reflective element was obtained. The total light transmittance of the light transmitting layer was 77.5%.
【００４４】次に、この光透過性層のキューブコーナー
型突起を有する面に、酸化チタン屈折率約2.6を真空蒸
着法にて、厚み約0.1μmで積層形成し、高屈折率光透過
層とした。高屈折率光透過層の全光線透過率は86.3％で
あった。Next, a titanium oxide refractive index of about 2.6 was formed on the surface of the light transmitting layer having the cube-corner projections to a thickness of about 0.1 μm by vacuum evaporation to form a high refractive index light transmitting layer. did. The total light transmittance of the high refractive index light transmitting layer was 86.3%.
【００４５】さらに、この高屈折率光透過層を別途、予
め剥離紙〔リンテック(株)製 EA2P-SLPE〕上に形成した
厚み40μm、色相Ｌ* 87.3、ａ* -1.9、ｂ* -1.6の白色
粘着剤層（本発明の低屈折率樹脂層に当たる）〔日本カ
ーバイド工業(株)製アクリル系粘着剤「ニッセツ KP-17
39」100重量部、日本カーバイド工業(株)製架橋剤「ニ
ッセツ CK-101」３重量部、及び、特殊色料工業(株)製
着色剤「マルコ480」16重量部により調整〕と貼り合わ
せ、本発明の再帰反射シートを得た。粘着剤層用樹脂の
屈折率は1.5であった。Further, this high-refractive-index light-transmitting layer was separately formed on a release paper (EA2P-SLPE, manufactured by Lintec Co., Ltd.) in a thickness of 40 μm, with a hue L * 87.3, a * -1.9 and b * -1.6. White pressure-sensitive adhesive layer (corresponding to the low refractive index resin layer of the present invention) [Nippon Carbide Industry Co., Ltd. acrylic pressure-sensitive adhesive "Nissetsu KP-17"
39 ”100 parts by weight, 3 parts by weight of Nissetsu CK-101, a cross-linking agent manufactured by Nippon Carbide Industry Co., Ltd., and 16 parts by weight of a coloring agent“ Marco 480 ”manufactured by Tokusetsu Kogyo Kogyo Co., Ltd.) Thus, a retroreflective sheet of the present invention was obtained. The refractive index of the resin for an adhesive layer was 1.5.
【００４６】得られた再帰反射シートは表１に示すごと
く、白度に優れ、かつ反射性能に優れる本発明の目的を
十分に達成するものであった。As shown in Table 1, the obtained retroreflective sheet sufficiently achieved the object of the present invention which is excellent in whiteness and excellent in reflection performance.
【００４７】比較例１ 酸化チタンのかわりに金属アルミニウムを真空蒸着法に
て、厚み約0.15μm積層形成した以外は全て実施例１と
同様にして再帰反射シート得た。得られた再帰反射シー
トは表１に示すごとく、金属色のくすみのある白度に劣
る本発明の目的を達しないものであった。Comparative Example 1 A retroreflective sheet was obtained in the same manner as in Example 1 except that aluminum was laminated in a thickness of about 0.15 μm by vacuum evaporation instead of titanium oxide. As shown in Table 1, the obtained retroreflective sheet did not achieve the object of the present invention, which was poor in whiteness with a dull metallic color.
【００４８】比較例２ カプセルキューブコーナー型再帰反射シートとして３Ｍ
社製ダイヤモンドグレートを用い性能を比較した。シー
トは表１に示すごとく、水浸漬後の外観に劣る本発明の
目的を達しないものであった。Comparative Example 2 3M as a capsule cube corner type retroreflective sheet
The performance was compared using a diamond great made by the company. As shown in Table 1, the sheet was inferior in appearance after immersion in water and did not achieve the object of the present invention.
【００４９】[0049]
【表１】 [Table 1]
【００５０】[0050]
【発明の効果】本発明によれば、再帰反射性要素を含む
光透過性層と、その背面に積層形成された高屈折率光透
過層と、さらにその背面に積層された低屈折率層によ
り、白度あるいは彩度の高い反射シートが、また、水等
の侵入による反射性能低下の心配がない優れた反射シー
トが非常に簡単な工程で生産効率よく製造できる。According to the present invention, a light-transmitting layer including a retroreflective element, a high-refractive-index light-transmitting layer laminated on the back surface, and a low-refractive-index layer laminated on the rear surface are further included. In addition, a reflection sheet having high whiteness or saturation and an excellent reflection sheet having no fear of a decrease in reflection performance due to invasion of water or the like can be manufactured with a very simple process with high production efficiency.
Claims (2)
光透過性層と、その背面に積層形成された高屈折率光透
過層と、さらにその背面に積層された低屈折率層とから
なるキューブーコーナー型再帰反射シートにおいて、該
高屈折率光透過層が硫化亜鉛、二酸化チタン、酸化鉛か
ら選ばれる薄層であり、該高屈折率光透過層が直接再帰
性反射要素に積層され、該低屈折率層が接着剤樹脂層で
あり、該低屈折率層が直接高屈折率光透過層に積層され
ていることを特徴とするキューブコーナー型再帰反射シ
ート。1. A cue comprising a light-transmitting layer including a cube-corner type retroreflective element, a high-refractive-index light-transmitting layer laminated on the rear surface thereof, and a low-refractive-index layer laminated further on the rear surface thereof. In the Boo-corner type retroreflective sheet ,
Whether the high refractive index light transmission layer is zinc sulfide, titanium dioxide, or lead oxide
The high refractive index light transmission layer is a thin layer selected from
Laminated on a reflective element, and the low refractive index layer is an adhesive resin layer.
The low refractive index layer is directly laminated on the high refractive index light transmitting layer.
Cube corner type retroreflective system
To
層の屈折率ｎ２においてｎ１／ｎ２が1.42以上であるこ
とを特徴とする請求項１記載のキューブコーナー型再帰
反射シート。2. A cube-corner of claim 1, wherein n 1 / n 2 at the refractive index n 2 of the refractive index n 1 of the high refractive index light-transmitting layer low refractive index layer is equal to or is 1.42 or more Retroreflective sheet.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16504093A JP3221771B2 (en) | 1993-06-11 | 1993-06-11 | Cube corner type retroreflective sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16504093A JP3221771B2 (en) | 1993-06-11 | 1993-06-11 | Cube corner type retroreflective sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06347622A JPH06347622A (en) | 1994-12-22 |
| JP3221771B2 true JP3221771B2 (en) | 2001-10-22 |
Family
ID=15804698
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16504093A Expired - Fee Related JP3221771B2 (en) | 1993-06-11 | 1993-06-11 | Cube corner type retroreflective sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3221771B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6172810B1 (en) | 1999-02-26 | 2001-01-09 | 3M Innovative Properties Company | Retroreflective articles having polymer multilayer reflective coatings |
| US6503564B1 (en) | 1999-02-26 | 2003-01-07 | 3M Innovative Properties Company | Method of coating microstructured substrates with polymeric layer(s), allowing preservation of surface feature profile |
| US6894615B2 (en) * | 2001-10-09 | 2005-05-17 | 3M Innovative Properties Company | Article with retroreflective and radio frequency-responsive features |
| EP2103972B1 (en) | 2008-03-20 | 2014-04-23 | 3M Innovative Properties Company | Light device comprising light guide |
| EP2343198A1 (en) | 2010-01-12 | 2011-07-13 | 3M Innovative Properties Company | Security laminate, method of making a security laminate, and article comprising a security laminate |
| US9651721B2 (en) | 2012-08-27 | 2017-05-16 | Avery Dennison Corporation | Retroreflector with low refractive index backing |
-
1993
- 1993-06-11 JP JP16504093A patent/JP3221771B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06347622A (en) | 1994-12-22 |
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