JP2003084113A - Fluorescent retroreflective sheet - Google Patents

Abstract

(57) [Problem] To provide a fluorescent retroreflective sheeting excellent in fluorescent appearance and light resistance of fluorescent color. SOLUTION: At least one of a surface protective layer, a retroreflective element layer, and a layer between the surface protective layer and the retroreflective element layer is provided in at least a retroreflective layer comprising the surface protective layer and the retroreflective element layer. A fluorescent retroreflective sheet containing a specific fluorescent colorant.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel fluorescent retroreflective sheet. More specifically, the present invention relates to a novel fluorescent retroreflective sheet containing a fluorescent colorant having a specific structure.

In particular, the present invention is directed to signs such as road signs and construction signs, license plates for vehicles such as automobiles and motorcycles, safety materials such as clothing and life preservers, markings for signs, visible light, laser light or The present invention relates to a fluorescent retroreflective sheet, which is useful in a reflection plate of infrared light reflection type sensors and is composed of a cube-corner retroreflective element and a micro glass-sphere retroreflective element.

[0003]

2. Description of the Related Art Conventionally, a retroreflective sheet which reflects incident light toward a light source is well known.
The sheet utilizing its retroreflective property is widely used in the above-mentioned fields of use.

Generally, the basic optical characteristics desired for a retroreflective sheet are high brightness at night, that is, the height (size) of the reflected brightness represented by the reflected brightness of light incident from the front of the sheet. And wide angle, and further,
Regarding the wide-angle property, three performances of an observation angle characteristic, an incident angle characteristic, and a rotation angle characteristic are required. Further, the visibility of the sheet during the day is also required to be excellent.

[0005] Several improvements have been reported in the past for the purpose of improving the visibility of the retroreflective sheet during the daytime. It is generally known to include colorants to give a fluorescent appearance.

For example, in US Pat. No. 3,830,682 to Rowland, Rhodami is used for the prism layer of a triangular-pyramidal cube-corner retroreflective sheet.
neB Extra, Rhodamine 6DGN,
Fluorol 7GN and Amaplast Oran
By incorporating a fluorescent colorant such as ge LFP,
It is disclosed that a fluorescent retroreflective sheet having a clear color tone can be prepared.

In US Pat. No. 5,387,458 to Pavalka, a screen layer which is substantially transparent to visible light and absorbs ultraviolet rays, and Thio
indigoid system, Thioxanthene system, B
Enzoxazole Coumarin system or Pe
Disclosed is a fluorescent retroreflective sheet having a vivid color tone, which is composed of a triangular pyramidal cube-corner retroreflective element layer to which a rylene image-based dye is added.

In US Pat. No. 5,605,761 to Burns, a triangular-pyramidal cube-corner retroreflective element layer is provided with a Thixanthone-based, Pe-based
rylene image system or Thioindig
Disclosed is a fluorescent retroreflective sheet having a clear color tone, to which an oid based fluorescent colorant and a hindered amine based light stabilizer are added.

Further, in US Pat. No. 5,672,643 to Burns, a reflective element layer of a cube-corner retroreflective sheet has a specific structure of Perylene.
Eimide fluorescent colorant and Lumogen F Ye
low 083, CI Solvent Yellow
160: 1, CI Solvent Green
4, CI Pigment Yellow 101, C
I Solvent Yellow 131, CI So
lvent Yellow 98, Oraset Ye
low 8GF, CI Solvent Green
5 and a fluorescent retroreflective sheet with a specific range of tones containing a combination with a specific fluorescent colorant selected from Golden Yellow D304.

However, none of the fluorescent retroreflective sheets proposed in the above patents simultaneously satisfy both an excellent fluorescent appearance and weather resistance for maintaining those fluorescent colors.

Regarding the coumarin-based compound of [Chemical Formula 1],
It is described in Japanese Patent No. 3192316 of Murakami et al. Of Nippon Kayaku Co., Ltd.

For the benzopyran compound of the formula [2], see Endo et al., Mitsubishi Chemical Corporation, JP 2001-555.
No. 23 publication.

The coumarin-based compound represented by [Chemical Formula 3] is described in Japanese Patent Laid-Open No. 2001-81347 of Teruda et al., Mitsubishi Chemical Corporation.

Regarding the fluorescent diketopyrrolopyrrole represented by [Chemical formula 4], refer to Ciba Specialty Chemicals Holding, Inc.
1-97975.

However, these four publications do not describe the use of these fluorescent colorants in the retroreflective sheet.

In addition, the pair of triangular-pyramidal retroreflective elements sharing the bottom (x) share opposite side surfaces (c).
Regarding an element having a shape in which the ₁ plane and the c ₂ plane) are symmetric, International Publication WO98 by Mimura et al.
/ 18028, JP-A-11-149006, JP-A-11-305018 and the like.

In these publications, in order to improve the luminance characteristics as a retroreflective sheet, the optical axis of a triangular pyramid type retroreflective element is inclined, and the reflection efficiency of an inclined triangular pyramid type cube corner retroreflective element is improved. For the purpose of improvement, in order to make the areas of the three reflecting surfaces equal, at least one of the three V-shaped grooves forming the triangular-pyramidal cube-corner retroreflective element is compared with other grooves. It also describes cutting deep or shallow.

However, in these publications, the side surfaces (c) of the pair of triangular-pyramidal retroreflective elements facing each other are described.
It is not described that the incident angle characteristic and the observation angle characteristic are further improved by making the _1st surface and the c ₂ surface) different shapes.

[0019]

DISCLOSURE OF THE INVENTION The present inventors have found a fluorescent colorant having both excellent fluorescent appearance and weather resistance capable of maintaining its fluorescent color for a long period of time, which can be used in a retroreflective sheeting. As a result of various studies and a study of a retroreflective element to improve the luminance characteristics of the retroreflective sheet, a certain coumarin-based and benzopyran-based fluorescent colorant and a fluorescent diketopyrrolopyrrole were found to be both of the above. The inventors have found that they have characteristics, and have found that excellent luminance characteristics and excellent fluorescent appearance and light resistance can be obtained by using them in a specific retroreflective sheet, and have completed the present invention.

Thus, according to the present invention, there are provided a surface protective layer disposed on the side where light is incident, a binder layer connected to the surface protective layer via a network-shaped bonding portion, a surface protective layer and a binder layer. An air layer hermetically sealed by a mesh connection between
And a hermetically sealed retroreflective sheet comprising a retroreflective element layer provided between the surface protective layer and the air layer or the binder layer and the air layer, wherein at least one layer closer to the incident light side than the enclosed air layer is Formula (1)

[0021]

[Chemical 1]

(Wherein R ¹ and ² each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), or a coumarin-based compound represented by the formula (2)

[0023]

[Chemical 2]

(In the formula, R _{1 to} R ₄ each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₅ represents an alkyl group which may have a substituent, an aryl group or a heteroaryl group. represents, X is -CO- or -SO ₂ - represents a group).
A benzopyran compound represented by or a formula (3)

[0025]

[Chemical 3]

[Wherein, Z ₁ , Z ₂ , Z ₃ and Z ₄ represent a nitrogen atom or a carbon atom, and at least one of Z _{1 to} Z ₄ represents a nitrogen atom; R ₁ , R ₂ , R ₃ And when R ₄ is bonded to a carbon atom, each independently represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, an amino group, a dialkylamino group, a diarylamino group, a hydroxyl group, an alkoxy group,
It represents an aryloxy group, a mercapto group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, an alkyl group or an aryl group, and two adjacent groups may combine to form a ring. R ₁ , R ₂ , R ₃ and R ₄ represent unsubstituted when bonded to a nitrogen atom. R ₅ , R ₆ , R
₇ and R ₈ each independently represent an alkyl group having 1 to 6 carbon atoms. X is an oxygen atom, a sulfur atom, -NH-, or-
NR ₉ −, and Y is ═O, ═NH, or ═NR _10.
Is. (R ₉ and R ₁₀ represent an alkyl group having 6 or less carbon atoms, or a cycloalkyl group.)], Or a formula (4).

[0027]

[Chemical 4]

[In the formula, R₁And R_TwoAre independent of each other,
C₁-C₂₅Alkyl, allyl (this is C₁-C_ThreeA
Rukiru is Ar_ThreeCan be replaced 1 to 3 times with
), -CR_ThreeR_Four-(CH_Two)_m-Ar_Three(here,
R_ThreeAnd R_FourIndependently of one another, hydrogen or C₁-C
_FourMeans alkyl, or phenyl (which means C ₁
-C_ThreeCan be substituted 1-3 times with alkyl
Means Ar, Ar_ThreeIs phenyl, or 1- or 2
-Naphthyl (this is C₁-C₈Alkyl, C₁-C₈
Alkoxy, halogen or phenyl (this is C₁
-C₈Alkyl, C₁-C₈Substitute 1-3 times with alkoxy
Can be replaced) 1-3 times.
And m means 0, 1, 2, 3 or 4.
Taste, where C₁-C₂₅Alkyl or -CR_ThreeR
_Four-(CH_Two)_m-Ar_Three, Preferably C₁-C₂₅A
Luquil is a functional group that can increase solubility in water,
For example, a tertiary amino group, -SO_Three ⁻Or PO_Four ^2-Set in
Can be exchanged, Ar₁And Ar_TwoAre each other
Independently, the following formula:

[0029]

[Chemical 5]

In the above formula, R₅Is C₁−
C₆Alkyl, -NR₈R₉, -OR ₁₀, -S (O)
_nR₈, -Se (O)_nR₈, Or phenyl (this is C
₁-C ₈Alkyl or C₁-C₈1 to 1 with alkoxy
Can be substituted three times), where
R₈And R₉Independently of each other, hydrogen, C₁-C₂₅A
Rukiru, C₅-C₁₂Cycloalkyl, -CR_ThreeR_Four−
(CH_Two) M-ph, R ₁₀(Where R₁₀Is C₆−
C₂₄Meaning aryl) or 5 to 7 ring atoms
A saturated or unsaturated heterocyclic group containing (wherein the ring is a carbon atom
1 to 3 selected from the group consisting of a child, nitrogen, oxygen and sulfur
4 heteroatoms), where ph, a
The reel and the heterocyclic group are C₁-C₈Alkyl, C₁-C
₈Substituted one or three times with alkoxy or halogen
Or R₈And R₉Is -C
(O) R₁₁(Where R₁₁Is C₁-C₂₅Archi
Le, C₅-C₁₂Cycloalkyl, R₁₀, -OR₁₂
Or-NR_ThirteenR₁₄(Where R₁₂, R_ThirteenOver
And R₁₄Is C₁-C₂₅Alkyl, C₅-C₁₂Shiku
Lower alkyl, C₆-C₂₄Means aryl)
Or saturated or unsaturated containing 5 to 7 ring atoms.
A saturated heterocyclic group (where the ring is a carbon atom, nitrogen, oxygen and
And 1 to 3 heteroatoms selected from the group consisting of
Consisting of), wherein the aryl and heterocyclic groups are
Is C₁-C₈Alkyl or C₁-C₈Alkoxy
1 to 3 times, or -N
R₈R₉Is R₈And R₉Together, Tetramethy
Len, pentamethylene, -CH_Two-CH_Two-O-CH_Two
-CH_Two-Or-CH_Two-CH_Two-NR₅-CH_Two
-CH_Two-, Preferably -CH_Two-CH_Two-O-CH
_Two-CH_TwoMeans a 5- or 6-membered heterocyclic group, which means-
n means 0, 1, 2, or 3, and where R₆
And R₇Independently of one another, hydrogen or R₅Means
At the same time does not mean hydrogen, and preferably R₆Is R₅
Means R₇Means hydrogen.]
Fluorescent colorant selected from the group consisting of ketopyrrolopyrroles
A fluorescent fluorescent compound containing at least one of
A retroreflective sheet is provided.

Hereinafter, the fluorescent retroreflective sheet of the present invention will be described in more detail.

The present invention is directed to a surface protective layer provided on the side where light is incident, a binder layer connected to the surface protective layer through a mesh-shaped joint, and between the surface protective layer and the binder layer. Encapsulation of a hermetically sealed retroreflective sheet comprising an air layer hermetically sealed by a mesh-shaped joint portion, and a retroreflective element layer provided between the surface protective layer and the air layer or the binder layer and the air layer. In the layer closer to the incident light side than the air layer, the coumarin-based fluorescent colorant of the formula (1) and / or the benzopyran-based fluorescent colorant of the formula (2) and / or the coumarin-based compound of the formula (3) and / or the formula (3) By incorporating the fluorescent diketopyrrolopyrrole of 4), a fluorescent color is imparted to the retroreflective sheet.

The hermetically sealed retroreflective sheet capable of imparting a fluorescent color according to the present invention is not particularly limited in its constitution as long as it basically has the above constitution, and any known per se is used. The present invention can be applied to a retroreflective sheet.

The coumarin-based fluorescent colorant of the formula (1) used for imparting a fluorescent color to the retroreflective sheet is known per se (see Japanese Patent No. 3192316), and here, with reference to the publication. Replace with the description.

The benzopyran-based fluorescent colorant of the formula (2) used for imparting fluorescence to the retroreflective sheet is also known per se (Japanese Patent Laid-Open No. 2001-5552).
(See Japanese Patent Publication No. 3), and here, the reference is replaced with the description.

The coumarin-based fluorescent colorant of the formula (3) used for imparting a fluorescent color to the retroreflective sheet is known per se (see Japanese Patent Application Laid-Open No. 2001-81347). Replace the description with a quote.

The fluorescent diketopyrrolopyrrole of the formula (4) used for imparting fluorescence to the retroreflective sheet is also known per se (JP 2001-9797A).
(See Japanese Patent Laid-Open No. 5), the description of which is here replaced by the citation of the publication.

The compounding amount of the fluorescent colorants of the above formulas (1) to (4) is not strictly limited, and may be in a wide range depending on the use of the retroreflective sheet of the present invention and the desired degree of fluorescence. Can vary over a period of time, but generally 0.0
A range of 1 to 0.5 PHR, particularly 0.02 to 0.4 PHR is preferable.

In the hermetically sealed retroreflective sheeting according to the present invention, the coumarin-based fluorescent colorant of formula (1) and formula (2)
The benzopyran-based fluorescent colorant, the coumarin-based fluorescent colorant of the formula (3), and the fluorescent diketopyrrolopyrrole of the formula (4) are
Each can be used alone or two or more types can be used in combination. Further, it can be used in combination with other fluorescent colorants, non-fluorescent dyes, pigments and the like.

The retroreflective layer and / or the surface protective layer and / or the layer containing the fluorescent colorant of the retroreflective sheet of the present invention may optionally contain an ultraviolet absorber for the purpose of improving weather resistance. be able to. Examples of UV absorbers that can be blended include the following. Hydroquinone series: Hydroquinone, hydroquinone disalicylate, etc. Salicylic acid type: phenyl salicylate,
Paraoctyl phenyl salicylate etc. Benzophenone type: 2-hydroxy-4-methoxybenzophenone, 2-
Hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone,
2,4-hydroxybenzophenone, 2,2'-hydroxy 4,4'-dimethoxybenzophenone, 2-hydroxy-4
-Benzoyloxybenzophenone, 2,2'-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfonebenzophenone, 2,2 ', 4,4'
-Tetrahydroxybenzophenone, 2,2'-hydroxy-4,4'-dimethoxy-5-sodium sulfobenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-5-chlorobenzophenone and the like. Benzotriazole type: 2- (2'-hydroxy-
5'-methylphenyl) benzotriazole, 2- (2 '
-Hydroxy-5'-methylphenyl) -5-carboxylic acid butyl ester benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) -5,6-dichlorobenzotriazole, 2- (2'-hydroxy- 5'-methylphenyl)
-5-ethylsulfone benzotriazole, 2- (2'-hydroxy-5'-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'tert-butylphenyl) benzotriazole, 2 -(2'-hydroxy
-5'-amylphenyl) benzotriazole, 2-
(2'-hydroxy-3 ', 5'-dimethylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-
Dimethylphenyl) -5-methoxybenzotriazole,
2- (2'-methyl-4'-hydroxyphenyl) benzotriazole, 2- (2'-stearyloxy-3 ', 5'-
Dimethylphenyl) -5-methylbenzotriazole, 2
-(2'-Hydroxy-5-carboxylic acid phenyl) benzotriazole ethyl ester, 2- (2'-hydroxy-
3'-methyl-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-ditert-butylphenyl) -5-chloro-benzotriazole, 2-
(2'-Hydroxy-5-methoxyphenyl) benzotriazole, 2- (2-hydroxy-5'-phenylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-cyclohexylphenyl) benzotriazole 2- (2'-hydroxy-4 ', 5'-dimethylphenyl-5-carboxylic acid benzotriazole butyl ester,
2- (2'-hydroxy-3 ', 5'-dichlorophenyl)
Benzotriazole, 2- (2'-hydroxy-4 ',
5'-dichloro) benzotriazole, 2- (2'-hydroxy-3 ', 5'-dimethylphenyl) -5-ethylsulfone benzotriazole, 2- (2'-hydroxy-5'-
Phenylphenyl) benzotriazole, 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-methoxyphenyl)-
5-methylbenzotriazole, 2- (2'-hydroxy-
5'-methylphenyl) -5-carboxylic acid ester benzotriazole, 2- (2'-acetoxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-ditertiary butylphenyl) -5-chlorobenzotriazole and the like. Cyanoacrylate-based: 2-cyano-3,3-diphenylethyl acrylate, 2-cyano-
2-Ethylhexyl 3,3-diphenylacrylate and the like.

Of these ultraviolet absorbers, those of benzophenone type and benzotriazole type are preferable,
Above all, in the benzophenone series, 2,3'-dihydroxy-
4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone and 2,2 ', 4,4'
-Tetrahydroxybenzophenone; 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5-methylphenyl) -5,6-dichlorobenzotriazole in the benzotriazole system,
2- (2-hydroxy-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-methyl-
5'-tert-butylphenyl) benzotriazole, 2-
(2'-Hydroxy-3 ', 5'-ditertiarybutylphenyl) -5-chloro-benzotriazole, 2- (2'-hydroxy-5'-phenylphenyl) -5-chlorobenzotriazole, 2- ( 2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-5'-octoxyphenyl) benzotriazole and the like are effective.

Further, in the commercially available product, a benzotriazole-based or benzophenone-based ultraviolet absorber can be used as the ultraviolet absorber, and as an example of the benzotriazole-based ultraviolet absorber, Seesorb 701, 702 manufactured by Cypro Kasei Co., Ltd. , 703, 704, 706, 709;
Asahi Denka Co., Ltd. ADEKA STAB LA31, LA32;
Sumitomo Chemical Co., Ltd. Sumisorb 250; Kyoyaku Co., Ltd. Biosorb 590, and the like, and examples of benzophenone-based UV absorbers include Asahi Denka Co., Ltd. Adeka Stab 1413, LA51; Cipro Kasei Co., Ltd. Sea soap 1001 and 103; Sumitomo Corporation Sumisorb 110S and the like.

The amount of these ultraviolet absorbers added is usually
It is preferably in the range of 0.01 to 2 PHR, particularly 0.01 to 1 PHR, and more preferably 0.1 to 0.95 PHR.

Further, the layer containing the fluorescent colorant of the retroreflective sheet of the present invention has the purpose of improving weather resistance.
If necessary, a hindered amine light stabilizer can be added. As a hindered amine light stabilizer that can be used in that case, since it can maintain weather resistance,
A piperidine-type hindered amine light stabilizer having a tertiary amine structure having a molecular weight of 600 or more is particularly preferable. Examples of hindered amine light stabilizers that can be used include:

[0045]

[Chemical 6]

Those having structural formulas such as

Examples of commercially available products include TINUVIN 622LD, 765, 144, manufactured by Nippon Ciba Geigy Co., Ltd.
KIMASORB 119FL; ADEKA STAB LA52 and LA62 manufactured by Asahi Denka Kogyo Co., Ltd., Sanol LS2626 manufactured by Sankyo Co., Ltd., and the like.

These hindered amine light stabilizers, alone or in combination with an ultraviolet absorber or an antioxidant, are usually 0 to 1 PHR, preferably 0.1 to 1 PHR, and particularly preferably 0.2 to 0.8 PHR. Can be incorporated into the layer containing the fluorescent colorant in an amount within the range.

Further, the above light stabilizer can be introduced into the skeleton of the resin constituting the layer containing the fluorescent colorant, for example, in the form of an ester with (meth) acrylic acid. Examples of such reactive light stabilizers are 1, 2, 2,
6,6-pentamethylpiperidylmethacrylate, 2,2,6,6-tetramethylpiperidylmethacrylate, etc. are mentioned, and these are other reactive monomers constituting the resin, for example, (meth) acrylic acid esters, A light stabilizer group can be introduced into the resin skeleton by copolymerization with vinyl acetate, vinyl chloride or the like.

Further, a layer containing a fluorescent colorant may be blended with a benzoate light stabilizer or the like for the purpose of imparting weather resistance. Examples of benzoate-based light stabilizers that can be used include benzoate-type quenchers, for example, Tinuvin 1 manufactured by Nippon Ciba-Geigy Co., Ltd.
20 (brand name) can be illustrated.

Hereinafter, the fluorescent retroreflective sheet of the present invention will be described in more detail with reference to the drawings.

The retroreflective sheeting of the present invention will be described first with reference to FIG. 1 which is a sectional view of one embodiment of a preferred structure of a cube-corner retroreflective sheeting.

In FIG. 1, (4) is a retroreflective element layer in which triangular-pyramidal cube-corner reflective elements are arranged in a close-packed manner, and (3) is a holder layer for holding the retroreflective element. The retroreflective element layer (4) and the holder layer (3) are usually integrated (5), but separate layers may be laminated. The retroreflective element layer (4) includes a surface protective layer (1) and a printing layer (for transmitting information to an observer or coloring the sheet, depending on the intended use of the retroreflective sheet, the operating environment, etc.). 2), a binder layer (7) for achieving an enclosed and sealed structure for preventing moisture from entering the back surface of the retroreflective element layer (4), and a support layer supporting the binder layer (7). (8), an adhesive layer (9) and a release material layer (10) for attaching the retroreflective sheet to another structure can be provided (for details, see P.
(See CT International Publication WO98 / 18028).

The printing layer (2) is usually the surface protective layer (1).
And the reflective element layer (4) or the surface protection layer (1)
Or on the reflective side surface of the reflective element layer (4), and usually by means of gravure printing, screen printing, inkjet printing or the like.

Cube corner type retroreflective element layer (4)
Can be made of a polycarbonate resin, an acrylic resin, a vinyl chloride resin, or a urethane resin. Additives such as an ultraviolet absorber, a light stabilizer and an antioxidant may be added to the retroreflective element layer individually or in combination for the purpose of improving weather resistance. Further, as a colorant, various organic pigments, inorganic pigments, fluorescent pigments, non-fluorescent colorants, the above formulas (1) to (4)
Other than the above, fluorescent colorants and the like can be contained.

The same resin as that used for the retroreflective element layer (4) can be used for the surface protective layer (1), and for the purpose of improving weather resistance, an ultraviolet absorber, a light stabilizer and an oxidation agent are used. Additives such as inhibitors can be blended alone or in combination. Further, various kinds of organic pigments, inorganic pigments, fluorescent pigments, non-fluorescent colorants, fluorescent colorants other than the formulas (1) to (4), and the like can be contained as colorants. Further, the surface protective layer (1) may be divided into two or more layers, and each layer may contain the above-mentioned various additives and colorants individually or in combination.

The material for forming the retroreflective element layer (4) is not particularly limited as long as it satisfies the flexibility which is one of the objects of the present invention.
Those having optical transparency and uniformity are preferable. Examples of materials that can be used to form the retroreflective element layer (4) in the present invention include polycarbonate resin, vinyl chloride resin, (meth) acrylic resin, epoxy resin, styrene resin, polyester resin, fluororesin, and polyethylene. Examples of the resin include olefin resins such as resins and polypropylene resins, cellulosic resins, urethane resins, and the like. Among them, polycarbonate resins, (meth) acrylic resins, vinyl chloride resins and urethane resins are preferable.

The retroreflective element layer (4) is generally provided with an air layer (6) on the back surface of the cube-corner retroreflective element in order to satisfy the conditions for total internal reflection. The retroreflective element layer (4) and the binder layer (7) are hermetically sealed by a mesh-like joint in order to prevent problems such as a decrease in the critical angle due to the intrusion of water and corrosion of the metal layer under the conditions of use. Is preferred.

As the method of hermetically sealing, for example, US Pat. Nos. 3,190,178 and 4,025,15 are cited.
The method disclosed in Japanese Utility Model Publication No. 9 and Japanese Utility Model Publication No. 50-28,669 can be used. Examples of the resin used for the binder layer (7) include (meth) acrylic resin, polyester resin, alkyd resin, and epoxy resin, and the bonding portion can be formed by an embossing method.
At that time, as a method of joining the retroreflective element layer (4) and the binder layer (7), a heat-fusible resin joining method, a thermosetting resin joining method, an ultraviolet-curable resin joining method known per se are used. An electron beam curable resin bonding method or the like can be appropriately adopted.

The binder layer (7) used in the present invention can be formed on the entire surface of the support layer (8), or at the joint portion with the retroreflective element layer (4), that is, at the joint portion by a printing method or the like. It is also possible to selectively install depending on the method.

Examples of the material constituting the support layer (8) include a film or plate made of the same resin as the resin constituting the retroreflective element layer (4) or a general film moldable resin, fiber, cloth, Metal foils or plates made of stainless steel or aluminum can be used alone or in combination.

The retroreflective sheeting of the present invention is prepared by
As the adhesive layer (9) used for sticking to a glass plate, a plastic plate or the like and the release material layer (10) for covering the adhesive layer, those known per se can be appropriately selected and used. . The adhesive for the adhesive layer (9) can be appropriately selected from pressure-sensitive adhesives, heat-sensitive adhesives, cross-linking adhesives and the like. As the pressure-sensitive adhesive, for example, polyacrylic acid ester adhesive obtained by copolymerizing acrylic acid ester such as butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, nonyl acrylate with acrylic acid, vinyl acetate, etc., silicone. A resin-based adhesive, a rubber-based adhesive, or the like can be used, and as the heat-sensitive adhesive, for example, an acrylic-based, polyester-based, or epoxy-based resin can be used.

According to the present invention, in the cube-corner type retroreflective sheet having the above-described structure, the incident light side (arrow 11 in FIG. 1) of the enclosed air layer (6) is used.
At least one layer close to
In FIG. 1, at least one of the surface protective layer (1), the printed layer (2), the support layer (3), and the retroreflective element layer (4).
Coumarin-based fluorescent colorant of the formula (1), benzopyran-based fluorescent colorant of the formula (2), and coumarin of the formula (3) in two layers, preferably the support layer (3) or the retroreflective element layer (4). System fluorescent colorant and at least one fluorescent colorant selected from the fluorescent diketopyrrolopyrroles of formula (4), as described above, optionally blended with an ultraviolet absorber and / or light stabilizer, whereby It is possible to obtain a cube-corner type fluorescent retroreflective sheet having excellent fluorescent appearance and weather resistance durability of its fluorescent color.

The above-mentioned layer such as the retroreflective element layer is mixed with the fluorescent colorant and the like by, for example, a method of kneading and melting with a resin, a method of dispersing and dissolving in a resin compounding liquid, and a method of dissolving with a solvent. It can be carried out by a method such as mixing with a resin compounding liquid.

The fluorescent colorant may be uniformly dispersed in a layer such as a retroreflective element layer, or alternatively, a fluorescent colored resin film containing the fluorescent colorant may be separately prepared to prepare a surface protective layer or a retroreflective layer. It may be laminated on the reflective element layer, or a resin solution containing the fluorescent colorant may be prepared and coated on one surface of the surface protective layer or the retroreflective element layer.

Next, a retroreflective sheet, which is another preferred embodiment of the present invention, will be described with reference to the drawings.

In the plan view of FIG. 3, the V-shaped grooves having substantially symmetrical cross sections intersect each other, so that three side surfaces (a ₁ surface, b ₁ surface, c
₁ face; a ₂ face, b ₂ face, c ₂ face;…), and a pair of triangular pyramidal cube-corner retroreflective elements are projected to one side on one bottom face (S-S ') in common The triangular pyramidal retroreflective elements are arranged in a close-packed manner so that the side faces (c ₁ face, c ₂ face) facing each other have one base (x).
Form a pair, and the bottom surface (S-S ') is a base (z, z) of _one side surface (a ₁ surface, a ₂ surface) of the pair of triangular-pyramidal retroreflective elements and The bottom of the other side surface (b ₁ surface, b ₂ surface) (y,
y) and a pair of triangular pyramidal retroreflective elements that share a base (x) and have a common side surface (c ₁ surface, c ₂ surface) that have different shapes. And
And the height from the bottom surface (S-S ') to the apex (hx ₁ , h
The triangular-pyramidal cube-corner retroreflective elements of the present invention having different x ₂ ) are shown.

In the cross-sectional view of FIG. 3, the bases shared by the side surfaces (c ₁ surface, c ₂ surface) of the pair of triangular pyramidal retroreflective elements (R ₁ , R ₂ ) facing each other ( x, x, ...) from the bottom surface (Sx-Sx ') to the vertex (H
The height up to ₁ ) is defined as hx _1, and the bases (z, z) of _one side surface (a ₁ surface, a ₂ surface) and the other side surface (b ₁ surface, b) of the _two triangular pyramidal retroreflective elements are set. The height from the common bottom surface (S-S ') that includes both bases (y, y) of the _two surfaces) to the vertex (H ₁ ) is hyz ₁
And hx ₁ is larger than hyz ₁ and the base (Sx-S
The height hx ₁ from x ') to the vertex (H ₁ ) is the lower surface (Sx-S
A triangular pyramid-shaped retroreflective sheet is shown which is larger than the height hx ₂ from x ') to the vertex (H ₂ ). At this time, hx ₁ is h so that the height ratio hx ₁ / hyz ₁ is in the range of 1.05 to 1.5.
The V-shaped groove forming the bottom side (x) is formed to be deeper than the V-shaped groove forming the other bottom sides (y, z) so as to be larger than yz ₁ .

Further, in the plan view and sectional view of FIG. 4, a pair of triangular-pyramidal retroreflective elements from the triangular-pyramidal cube-corner retroreflective element group shown in FIG. 3 is enlarged and shown.

The plan view and the cross-sectional view of FIG.
The symmetrical V-shaped grooves intersect each other,
Side faces (a₁Face b₁Face c₁Face; a
₂Face b ₂Face c₂A pair of triangular pyramids separated by faces; ...)
-Type cube-corner retroreflective elements are substantially optically matched
Has a similar shape, whereby the pair of triangular-pyramidal cubes
Although the directions of the retroreflective elements differ from each other by 180 °,
Three with qualitatively identical optical axes and the angle (θ) formed by the perpendicular
A pyramidal cube-corner retroreflective element is shown.

The pair of triangular-pyramidal cube-corner retroreflective elements shown in the plan view and cross-sectional view of FIG. 4 show that, in particular, the two retroreflective elements R ₁ and R ₂ are each base of a ₁ side and a ₂ plane (z, z, ......) and b ₁ side and b ₂
The bottom surface (S-S ') including each bottom surface (y, y, ...) and the bottom surface (x, x, ...) shared by the c ₁ and c ₂ surfaces of the two retroreflective elements facing each other. The bottom surface (Sx-Sx ') is not at the same level as the bottom surface (Sx-Sx'), and the bottom surface (Sx-Sx ') is deeper than the bottom surface (S-S') in the embodiment of Figs. 11 and 12. That the two retroreflective elements R ₁ and R ₂ face each other
The areas of the c ₁ and c ₂ surfaces are different, and an offset was given to the position of the V-shaped groove (x) so that the area of the c ₁ surface becomes larger than the area of the c ₂ surface. It is a feature.

In the plan view and the sectional view of FIG. 4, the triangular pyramidal cube-corner retroreflective element pair (R ₁ , R ₂ ) differs in direction from each other by 180 °, but They have the same optical axis inclination (θ), and the optical axis (t ₁ ) of _one element (R ₁ ) of the triangular pyramidal reflective element pair is the same as the optical axis (t ₁ ) Intersection (Q with common bottom surface (S-S ')
Distance to be ₁₎ the plain piece pairs from the encompasses base (x) that share the common bottom (S-S ') perpendicular to the plane (Lx-Lx') and (q _1), the apex of the element ( H ₁ ) to the common bottom (S-S ')
Difference (q ₁ −p) between the distance (p ₁ ) from the intersection (P ₁ ) between the perpendicular line drawn to the bottom and the bottom surface (S-S ′) to the vertical plane (Lx-Lx ′)
_A triangular-pyramidal reflective element is shown in which ₁ ) is tilted in the direction of plus (+). The other elements different heights (R ₂₎ also an optical axis (t ₂₎ is the optical axis (t ₂₎ and the common bottom surface (S-S ') and the element pair from the intersection (Q ₂₎ of the common but the distance to the shared base encompass (x) the common bottom (S-S ') perpendicular to the plane (Lx-Lx') (q 2), from the apex of the element (H ₂₎ The perpendicular line on the bottom surface (S-S ') and the bottom surface (S-
S the difference between the distance ') the intersection (from P ₂₎ said vertical plane (Lx-Lx between' _{up) (p 2) (q 2} -p 2) is inclined in a direction in which the positive (+). The tilt angles of the optical axes of these elements are different from each other by 180 °, but they have substantially the same tilt (θ) of the optical axis.

In the plan view and sectional views of FIGS. 5 to 6, there is shown a triangular-pyramidal cube-corner retroreflective element which is another embodiment of the present invention.

In the retroreflective element shown in the plan view and cross-sectional view of FIGS. 5 to 6, the V-shaped grooves having substantially symmetrical cross sections intersect each other so that three substantially right angles are formed. Crossing sides (a ₁ side, b ₁ side, c ₁ side; a ₂ side, b ₂ side, c ₂ side;
…), A pair of triangular-pyramidal cube-corner retroreflective elements separated by a pair of side faces (c ₁ face, c ₂ face)
Surface) has different shapes, and the bottom sides (z, z) of _one side surface (a ₁ surface, a ₂ surface) of the pair of retroreflective elements and the other side surface (b
Triangles with different heights (hx ₁ , hx ₂ ) from the common bottom surface (S-S ') to the vertices (H ₁ , H ₂ ) including the bases (y, y) of the _1st and _2nd faces A cone-shaped cube-corner retroreflective sheet is shown.

In the sectional view of FIG. 6, a pair of triangular pyramids is used.
Type retroreflective element (R₁, R₂) Opposite sides (c₁
Face c₂Bottoms (Sx-S) including the bottoms (x, x,…) shared by the faces
x ′) to the vertex (H₁)For up to
Height to hx₁And one of the two triangular-pyramidal retroreflective elements
Side (a₁Face a₂Base) (z, z) and the other side (b)₁
Face b₂A common bottom surface that includes both the bottom (y, y) of
(S-S ') to the vertex (H ₁) Up to hyz₁When
Together, hx₁Is hyz₁Smaller and the common bottom (Sx-S
x ′) to the vertex (H₁) Height up to hx₁Is another vertex (H₂)of
Height hx₂Larger pair of triangular-pyramidal retroreflective elements shown
Has been. At this time, the height ratio hx₁/ Hyz₁Is 0.67 to 0.95
Hx to be in the range₁Is hyz₁Bottom to be smaller
V-shaped groove forming side (x) forms other base (y, z)
It is formed to be shallower than the V-shaped groove.

The plan view of FIG. 6 shows that the V-shaped grooves whose cross sections are substantially symmetrical intersect each other, so that three side surfaces (a ₁ surface, b ₁ surface, c surface) intersecting at substantially right angles to each other. ₁ side; a ₂ side, b ₂ side, c ₂
A pair of triangular-pyramidal cube-corner retroreflective elements separated by planes; ...) form an optically similar shape,
As a result, the pair of triangular-pyramidal cube-corner retroreflective elements show a triangular-pyramidal cube-corner retroreflective sheet having substantially the same optical axis and the angle (θ) formed by the perpendicular line, although the directions differ from each other by 180 °. Has been done.

At this time, a pair of triangular-pyramidal retroreflective elements (R₁,
R₂) Two faces (c₁Face c₂Common)
The base (x) is formed by the other two bases (y, z)
Bottom of diamond (A₀-C₁-B₀-C₂) A pair of opposite intersections
(A₀, B₀), And a distant position (A₂, B₂)
Shaped, line segment (A₀, B₀) And a line segment (A₂, B₂) Distance from
The separation (offset amount) is, for example, two retroreflective elements (R₁,
R₂) Other opposite intersections (C ₁, C₂) ± 2 to ± 20% of the distance
Can be appropriately selected within the range. As a result, the bottom surface (Sx-Sx ')
Vertex from (H₁, H₂) Up to (hx₁, hx₂) Is different,
And, the two sides (c₁; J₁-J₂-K₂-K₁-
H₁) And other aspects (c₂; J₂-H₂-K₂) Have different shapes,
Retroreflective element (R₁) C₁The surface is the other retroreflective element (R₂) C₂
Larger than the face.

Further, the triangular-pyramidal cube-corner retroreflective element pairs of the present invention have directions of 180 ° different from each other, but have substantially the same optical axis inclination (θ). The optical axis (t ₁ ) of _one element (R ₁ ) of the reflective element pair is
The common bottom surface (S-S ') including the base (x) shared by the element pair from the intersection (Q ₁ ) of the optical axis (t ₁ ) and the common one bottom surface (S-S') The distance (q ₁ ) to the plane (Lx-Lx ') perpendicular to and the common bottom (S-S') from the vertex (H ₁ ) of the element
Point (P ₁ ) between the perpendicular line drawn to the ground and the common bottom surface (S-S ')
From the vertical plane (Lx-Lx ') to the distance (p ₁ ) (q
_It may be inclined in a direction in which ₁ −p ₁ ) becomes a minus (−) (hereinafter, this mode is referred to as a minus inclination (−) triangular pyramidal retroreflective element). Also, the other element (R
₂₎ the optical axis (t ₂₎ is the optical axis (t ₂₎ and the common single bottom (S-S ') intersection of the (Q ₂₎ from the element pair facing surface (c ₁ surface, (c ₂ face) Distance (q ₂ ) to a plane (Lx-Lx ') that includes the base (x) shared by them and is perpendicular to the common base (S-S')
And the vertical plane (Lx-Lx 'from the intersection (P ₂ ) of the perpendicular line drawn from the vertex (H ₂ ) of the element to the common bottom surface (S-S') and the bottom surface (S-S ') The distance (p ₂ ) to () and the difference (q ₂ −p ₂ ) may also be tilted in the negative (−) direction. The tilt angles of the optical axes of these elements are different from each other by 180 °, but they have substantially the same tilt (θ) of the optical axis.

A triangular pyramid type retroreflective element group of the present invention is formed.
The V-shaped groove (x, x, x, ...) in one direction
The two sets of bases in the other two directions (y, y and z,
z) bottom surface of the diamond (A₀-C₁-B₀-C₂One)
The pair of opposite intersections (c₁, C _Two) Match the distance. This
Slightly in the pitch of the V-shaped groove (x, x, x, ...)
Deviation is given to the bottom (x) of the V-groove (example
For example, the line segment (A₀, B₀) And a line segment (A₂, B₂) With
Distance) can be given. In addition, this offset
Repeatedly cut V-shaped grooves (x, x, x, ...)
The number of V-shaped grooves (x, x, x, ...)
It increases in proportion and gradually. The resulting triangular pyramid
Type retroreflective element (R₁, R₂) Gradually changing the asymmetry of
You can

In general, when a light ray passes through a minute aperture, the light ray is spread by a diffraction effect with an intensity inversely proportional to the area of the aperture through which the light ray passes. This spread improves the visibility of the reflected light to the observer (driver) far away from the light source (headlamp) (improvement of the observation angle characteristic). In a triangular-pyramidal retroreflective element, the openings through which light rays pass are the three sides of the triangular pyramid (a ₁ , b ₁ , c _1, or a ₂ , b ₂ , c
_It is the other surface (element bottom surface) surrounded by _two surfaces, and its area changes in proportion to the height of the element. If the height of the device is small, the aperture area is reduced, and therefore the spread of the reflected light is increased due to the increase of diffraction effect. According to the calculation based on the computer simulation by the light tracing method, the spread of the reflected light rapidly increases when the height of the device becomes 50 μm or less. However, if the element size is too small, the retroreflected intensity in the front direction where the light is incident decreases due to the excessive light spread.

The triangular pyramidal retroreflective element pair according to the present invention has a height from a common bottom surface (Sx-Sx ′) to the vertices (H ₁ , H ₂ ) of the _two elements (R ₁ , R ₂ ). Since (hx ₁ , hx ₂ ) are different from each other, the left and right elements can have different aperture areas, and the element with a small height can spread the retroreflected light due to the diffraction effect, improving the viewing angle characteristics. On the other hand, since the element with a large height maintains the retroreflective intensity without the diffraction effect becoming excessive, it is necessary to obtain a triangular-pyramidal cube-corner retroreflective sheet with excellent viewing angle characteristics and reflective intensity as a whole. Is possible.

Further, according to the triangular-pyramidal retroreflective element of the present invention, for example, as shown in the plan view and sectional view of FIG. 3 and the plan view and sectional views of FIGS. It is possible to obtain triangular-pyramidal cube-corner retroreflective sheets having different element heights. As a result, it is possible to obtain a new triangular pyramid type cube-corner retroreflective sheet having different retroreflective properties of light incident from the left and right. In the elements shown in the plan view and cross-sectional view of FIG. 3, the large-height element groups arranged on the right side of the drawing all have their optical axes inclined to the right direction and exhibit excellent retroreflection characteristics to the right direction. Since the optical axes of the small elements arranged on the left side of these figures are all tilted to the left, excellent viewing angle characteristics can be shown to the left.

Light of Trigonal Pyramidal Retroreflective Element in the Present Invention
Academic axis (t₁) Is the optical axis (t₁) And the common bottom surface (S-
Intersection with S ') (Q₁) To the base (x) shared by the element pair
Including a plane perpendicular to the common bottom surface (S-S ') (Lx-L
x ') distance (q₁) And the vertex of the element (H₁) From the
An intersection of a perpendicular line drawn on the bottom surface (S-S ') and the plane
(P ₁) To the vertical plane (Lx-Lx ') (p₁)When
Difference of (q₁−p₁) Is plus (+) or minus (-)
The optical axis (t₁) And the perpendicular (θ)
Is 0.5 to 12 °, preferably 0.6 to 10 °, more preferably 0.
Inclined to be 6 to 1.5 °. As a result, the optical axis
Because it is tilted, the recursive reflection is
It is difficult for the brightness to decrease.

The triangular-pyramidal retroreflective element (R ₁ ,
R ₂ ), as shown in the plan view and the cross-sectional view of FIGS. 3 to 4, is a pair of triangular pyramidal retroreflective elements (R ₁ , R ₂ ) facing each other (side faces c ₁ ). , c ₂ face) shared base (x, x,
, The height from the bottom surface (Sx-Sx ') to the vertices (H ₁ , H ₂ ) of the triangular-pyramidal retroreflective element (R ₁ , R ₂ ) is defined as hx _1, hx ₂ ,
One side surface (a _{1 of the two} triangular pyramidal retroreflective elements (R ₁ , R ₂ )
Face (a, face ₂ ) bottom (z, z) and the other side (b ₁ face, b)
_Two bases (y, y) and a common base (S-
When the height from S ') to the vertex (H ₁ ) is hyz ₁ ,
The hx ₁ is a triangular-pyramidal retroreflective element substantially larger than hyz ₁ , and the ratio is, for example, hx ₁ / hyz ₁ is 1.05 to 1.5,
Since it is preferably formed in the range of 1.07 to 1.4, various improvements in optical characteristics can be obtained.

Since this improvement is that hx ₁ is substantially larger than hyz ₁ , the area of the c ₁ surface can be made larger than that of the conventional inclined surface of c ₁ where hx ₁ and hyz ₁ are equal. Can be achieved in order. In particular, for light incident at an angle close to perpendicular to the c ₁ plane, in other words, for a large incident angle, c ₁
Since the surface area is increased, the improvement of the incident angle characteristics is remarkable.

Further, the improvement of the optical characteristics by increasing the area of the c ₁ surface is achieved by adjusting the distance (p) and the distance (q) in the triangular pyramid type reflective element having an inclined optical axis, especially in the triangular pyramid type reflective element. This is particularly noticeable when the optical axis is tilted in a direction in which the difference (q-p) in (1) becomes positive.

The normal triangular pyramid type reflection element having no optical axis inclination has a common base (x) by inclining the optical axis of the element so that the above-mentioned (q-p) becomes positive.
The area of the inclined planes (c ₁ , c ₂ ) with a smaller angle is smaller than the area of the c ₁ , c ₂ planes of the element whose optical axis is not inclined, which reduces the probability of three-sided reflection and retroreflection. is there. On the other hand, it is preferable that the areas of the three inclined surfaces are equal in order that the incident light ray is reflected by the three inclined side surfaces and is efficiently retroreflected. However, in the case of the slanted triangular pyramid type reflective element in which hx ₁ and hyz ₁ are equal, the area of the slanted surface (c ₁ , c ₂ ) having a common base with the other two surfaces (a ₁ , b ₁ and to be smaller as compared with a _2, b _2), the probability of retroreflection by trihedral reflection described above is reduced. For this reason, not only the retroreflection performance of light incident from the front (front reflection brightness) is degraded, but also the retroreflection performance (incident angle characteristic) when the incidence angle is increased.

On the other hand, in the present invention, contrary to the above, (q-
Even if the optical axis is tilted so that p) becomes negative, the incident angle characteristic is improved, but by tilting the optical axis of the element so that (q-p) becomes negative, The area of the inclined planes (c ₁ , c ₂ ) having a common base (x) becomes larger than the area before the inclination, and there is a drawback that the probability of three-sided reflection and retroreflection is reduced.

The minus-inclined triangular-pyramidal retroreflective element according to the present invention has a base (x, x, which is shared by the side surfaces (c ₁ surface, c ₂ surface) facing each other of many pairs of triangular-pyramidal retroreflective elements.
The height from the bottom surface (Sx-Sx ') including x, ...) to the apex (H ₁ ) of the triangular-pyramidal retroreflective element is defined as hx ₁ , and one side surface of the two triangular-pyramidal retroreflective elements ( a ₁ side, the bottom of a ₂ side) (z,
z) and the bottom surface (y, y) of the other side surface (b ₁ surface, b ₂ surface) together from one common bottom surface (S-S ') to the apex (H ₁ )
When up to a height of hyz _1, hx ₁ has a substantially smaller triangular-pyramidal retroreflective element than hyz _1, the ratio h
Especially when the x ₁ / hyz ₁ is formed in the range of 0.67 to 0.95, preferably 0.71 to 0.93, various improvements in optical properties are obtained.

[0090] This improvement, hx ₁ is to be substantially smaller than hyz _1, as compared with the inclined surface of c ₁ of hx ₁ and hyz ₁ are equal prior art, to reduce the area of the c ₁ surface Can be achieved to be able to.

In the present invention, the common bottom surface (Sx
-Sx ') a plurality of triangular-pyramidal cube-corner retroreflective elements having a plurality of bases (x, x, ...) Base (Sx-Sx') to the apex of the triangular-pyramidal reflective element pair (H ₁ ,
Distance to _{H 2) (hx 1, hx} 2) is 30Myuemu～400myuemu, especially above distance (hx _1, hx ₂₎ is 50 m to 200 m, especially 60~100μ
A cube-corner retroreflective sheet having m triangular pyramidal reflective elements is suitable.

If any of the heights (hx ₁ , hx ₂ ) of the reflective element is less than 30 μm, the size of the reflective element becomes too small, and the recursive effect is caused by the diffraction effect determined by the aperture area of the reflective element. The divergence of reflected light becomes excessive and the retroreflection performance deteriorates. Also, one of the heights (hx ₁ , hx ₂ ) is 400 μm
When it exceeds, the thickness of the sheet becomes excessively large, and it is difficult to obtain a flexible sheet, which is not preferable.

A pair of triangular pyramid cues according to the present invention
Bucorn retroreflective element (R₁, R₂) 3 reflective sides
(A₁Surface, b₁Surface, c₁Surface or a_TwoSurface, b_TwoSurface, c_Two
Angle formed by the surfaces (prism vertical angle; a₁Surface-b₁surface
Apex angle, b₁Surface-c₁Face angle, c ₁Surface-a₁Face angle, or
a_TwoSurface-b_TwoFace angle, b_TwoSurface-c_TwoFace angle, c_TwoSurface-a
The apex angle of 2 planes is a substantially right angle, but it is not strictly
It is not a right angle (90.000 °) in taste, but improves the observation angle characteristics.
Therefore, it is preferable to give a slight angle deviation from the right angle.
Yes. Giving a very slight angular deviation to the prism apex angle
Triangular pyramid cube corner retroreflective obtained by
The retro-reflected light from the device is diverged to an appropriate degree,
We can make improvements.

As a method of giving these angle deviations, at the time of cutting V-shaped grooves (x, y and z) in three directions forming a triangular pyramid type cube-corner retroreflective element, V-shape in at least one direction is used. The angle of the groove can be slightly deviated in a symmetrical manner from the angle at which the prism apex forms a right angle. The method of giving this deviation is achieved by using a symmetrical cutting tool.

As another method of giving these angle deviations, at the time of cutting the V-shaped grooves (x, y and z) in three directions forming the triangular pyramid type cube corner retroreflective element, at least one direction is cut. The angle of the V-shaped groove can be cut with a slight deviation from the angle at which the prism apex forms a right angle in an asymmetric shape. To give this deviation, use asymmetrical cutting tools,
This is achieved by slightly tilting the symmetrical cutting tool.

As described above, the angle of the V-shaped groove is set to the prism
Giving a slight deviation from the angle at which the apex forms a vertical
Three sides of the triangular-pyramidal retroreflective element formed by
(A ₁Surface, b₁Surface, c₁Surface or a_TwoSurface, b_TwoSurface, c_Two
Surface of each prism apex angle (a₁Surface-b₁Face angle,
b₁Surface-c₁Face angle, c₁Surface-a₁Face angle, or a_Twosurface
-B_TwoFace angle, b_TwoSurface-c_TwoFace angle, c_TwoSurface-a_TwoSummit
Angle (9) to at least one prism apex angle
It is possible to give a very slight angle deviation from (0.000 °).
This allows the reflected light from the triangular pyramid type reflective element to be completely reflected.
It is possible to diverge moderately from the direction of retroreflection
It Reflective side surface of the triangular-pyramidal retroreflective element in the present invention
(A₁Surface, b₁Surface, c₁Surface or a_TwoSurface, b_TwoSurface, c_Two
At least formed by intersecting faces)
The size of one prism apex is 90.000 ° ± (0.00
1 ° to 0.4 °), preferably ± (0.01 ° to 0.2 °)
The angle of the V-shaped groove is deviated so that it deviates slightly within
Is preferred.

A pair of triangular-pyramidal retroreflective elements sharing such a base are formed on the side surfaces (c ₁ surface, C ₂ surface) facing each other.
Even for the retroreflective sheeting that uses elements having different shapes (faces), the side faces (c
A surface protective layer (1), a printing layer (2), a binder layer (6), a support layer (7), an adhesive agent of a retroreflective sheet using an element having a symmetrical shape on _one surface, C ₂ surface) These can be provided similarly to the layer (8) and the release material layer (9).

Next, one mode of another preferred structure of the cube-corner retroreflective sheeting of the present invention will be described with reference to FIG. 2 which is a sectional view thereof.

In FIG. 2, a metallic specular reflection layer (12) is provided on the surface of the reflection element (4), and further, an adhesive phase and a release agent layer are provided on the specular reflection layer (12). Is directly contacted with and laminated. The cube-corner retroreflective sheet in this embodiment does not require an air layer to retroreflect on the principle of specular reflection, and thus does not require a binder layer and a support layer.

The triangular-pyramidal cube-corner type retroreflective sheet of the present invention is formed on the surface of the reflective element (4) by using aluminum such as vacuum deposition, chemical plating, and sputtering.
A specular reflection layer (12) made of a metal such as copper, silver or nickel can be provided. Among the methods of providing the specular reflection layer (12), the vacuum evaporation method using aluminum can lower the evaporation temperature, so that the thermal deformation of the retroreflective element in the evaporation process can be minimized and obtained. The color tone of the specular reflection layer (12) is also brightest, which is preferable.

The continuous vapor deposition processing apparatus for the aluminum specular reflection layer (12) comprises a vacuum container capable of maintaining a vacuum degree of about 7 to 9 × 10 ⁻⁴ mmHg, a base sheet installed therein, and its light incident side surface. An unwinding device that unwinds a prismatic raw sheet consisting of two layers of surface protective layers laminated on top, a winding device that winds up the vapor-deposited prismatic raw sheet, and electric heating in a graphite crucible between them. It consists of a heating device that can melt aluminum with a heater. Pure aluminum pellets with a purity of 99.99% by weight or more are put into the graphite crucible.
The surface of the retroreflective element is vapor-deposited on the surface of the specular reflection layer (12) with a thickness of, for example, 800 to 2000Å by aluminum atoms that have been melted and vaporized at a current of 115 to 120 A and a processing speed of 30 to 70 m / min. Can be done.

The triangular-pyramidal cube-corner retroreflective sheeting of the present invention is generally arranged in a close-packed manner on a metal belt as a concave shape in which the shape of the triangular-pyramidal reflective element described above is inverted. Cube corner molding die, and heat and press an appropriate resin sheet that is flexible and has excellent optical transparency and uniformity, as described below, to the molding die. Can be manufactured by reversing and transferring to a resin sheet.

A typical method for manufacturing the above-mentioned cube-corner molding die is described in detail in, for example, Stamm, US Pat. No. 3,712,706, and a method according to this method is also adopted in the present invention. be able to.

Specifically, for example, using a super hard bite (for example, a diamond bite, a tungsten carbide bite, etc.) with a tip angle of about 73.4 to 81.0 ° on a base material whose surface is ground flat, Depending on the shape of the target triangular pyramidal reflective element in two directions (for example, the y direction and the z direction in FIG. 9), the repeating pitch and groove depth in each direction (for example, hx in FIG. 10). ₁ , hyz ₁ and hx ₂ , hyz ₂ ), and the crossing angle with each other, the depth of the groove (hx ₁ , hyz ₁ and hx ₂ , h
yz ₂ ) and cut a V-shaped parallel groove with a substantially symmetrical cross-sectional shape, and then in the third direction (x direction), the tip angle is 64.
Using a similar super hard bite of about 5 to 46.5 °, the intersection angle of these two directions without passing through the intersection of the formed y-direction groove and z-direction groove (here, the acute angle is referred to as the “intersection angle”). By cutting the V-shaped parallel groove at a repeating pitch (repeating pitch of line x in FIGS. 9 and 11) that bisects the complementary angle of A micro-prism master block arranged in the closest packed state is prepared. In the present invention, at this time, the depth of the groove in the x direction (hx ₁ , hx ₂ ) may be the same as the depth of the groove in the y direction and the z direction (hyz ₁ , hyz ₂ ), but in the y direction and the z direction. It is preferable to make it deeper or shallower than the depth (hyz ₁ , hyz ₂ ) of the groove in the direction.

In a preferred embodiment of the present invention, the repeating pitch in the y and z directions is 100 to 810 μm in width, the groove depth (hyz ₁ , hyz ₂ ) is 50 to 400 μm, and the mutual crossing angle is 43 to 55 °. ,
The depth (hx ₁ , hx ₂ ) of the groove in the x direction is in the range of 75 to 600 μm.

As a base material that can be suitably used for forming the microprism mother die, Vickers hardness (JIS
Z 2244) is preferably a metal material having 350 or more, particularly 380 or more. Specifically, for example, amorphous copper, electrodeposited nickel,
Aluminum and the like can be mentioned, and examples of the alloy-based material can include copper-zinc alloy (brass), copper-tin-zinc alloy, nickel-cobalt alloy, nickel-zinc alloy, and aluminum alloy.

Further, as the above-mentioned base material, a synthetic resin material can be used, and the glass transition point of the base material is changed because it does not cause inconveniences such as softening during cutting and difficulty of high-precision cutting. It is preferable that the material is a synthetic resin having a Rockwell hardness (JIS Z 2245) of 70 or more, particularly 75 or more at 150 ° C or higher, particularly 200 ° C or higher. Specifically, for example, polyethylene terephthalate resin, Examples thereof include polybutylene phthalate resin, polycarbonate resin, polymethylmethacrylate resin, polyimide resin, polyarylate resin, polyether sulfone resin, polyetherimide resin and cellulose triacetate resin.

Next, a metal film is formed on the surface of the obtained microprism matrix by electroforming. By removing this metal coating from the surface of the mold,
A metal mold for use in molding the triangular pyramid-shaped corner cube retroreflective sheet of the present invention can be prepared.

Electroforming is generally performed, for example, in a 60 wt% aqueous solution of nickel sulfamate at 40 ° C. under a current condition of about 10 A / dm 2. When the electroformed layer is formed at a rate of, for example, 0.02 mm / hr or less, a uniform electroformed layer can be easily obtained. Problems such as missing parts are likely to occur.

The first-generation electroformed mold thus formed from the prism master mold can be repeatedly used as an electroformed master used for preparing a second-generation electroformed mold. Therefore, it is possible to make many electroformed dies from one prism master.

The plurality of electroformed dies thus prepared can be used after being precisely cut and then combined and joined up to the final size of the dies for forming the micro-prism sheet by the synthetic resin. As this joining method, a method of simply abutting the cut end faces or a method of welding the combined joining portions by a method such as electron beam welding, YAG laser welding, or carbon dioxide laser welding can be adopted.

The combined electroforming mold is used for molding synthetic resin as a mold for molding synthetic resin. Compression molding or injection molding can be adopted as the method of molding the synthetic resin.

The compression molding is carried out by, for example, compressing the formed thin-wall nickel electroforming mold, a synthetic resin sheet having a predetermined thickness, and a silicone rubber sheet having a thickness of about 5 mm as a cushioning material to a predetermined temperature. After inserting into the forming press and preheating for 30 seconds under a pressure of 10 to 20% of the forming pressure,
It can be performed by heating and pressurizing for about 2 minutes under the conditions of 0 to 250 ° C. and 10 to 30 kg / cm 2. After that, a prism molded product can be obtained by cooling to room temperature and releasing the pressure in the pressurized state.

Further, for example, the thickness formed by the above method is about
An 0.5 mm thin electroformed mold was joined by the above welding method to form an endless belt mold, and this belt mold was placed on a pair of rolls consisting of a heating roll and a cooling roll, rotated, and heated. The molten synthetic resin is supplied in the form of a sheet to the belt mold on the roll, pressure-molded with one or more silicone rolls, and then cooled to below the glass transition temperature on the cooling roll. Then, it is possible to obtain a continuous sheet-like product by peeling it off from the belt mold.

Hereinafter, the present invention will be described more specifically with reference to Examples.

Example 1 Bisuf manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Enol type polycarbonate resin "Iupilon H30
00 "100 parts by weight, R in [Chemical formula 1]₁, R _TwoTogether
0.1 parts by weight of an ethyl-based coumarin-based fluorescent colorant,
R in [Chemical 2] ₁~ R₅All are methyl groups and X is -CO-
0.1 parts of benzopyran-based fluorescent colorant and Sankyo Stock Association
Tetramethylpiperidine-based hindered amine
0.5 part by weight of Noll LS2626 "is sold to Mitsui Mining Co., Ltd.
Using a high-speed rotary mixer, Henschel Kimisa, manufactured by
Then, the mixture was mixed for 15 minutes under the condition that the rotation speed was 100 rpm.

Using a single screw extruder equipped with a screw having a screw length / diameter ratio of 30: 1 and a compression ratio of 3.0, the mixed resin was extruded at a temperature of 240 ° C. and a rotation speed of 35 rpm. After being extruded from a nozzle having a diameter of 4 mm, it was cooled with water and cut to obtain colored pellets.

After drying the colored pellets at 80 ° C. for 12 hours, the ratio of screw length to diameter was 30:
A single-screw extruder equipped with a screw having a compression ratio of 3.0 and a compression ratio of 3.0 was extruded under the conditions of an extrusion temperature of 240 ° C. and a rotation speed of 50 rpm to obtain a polycarbonate resin sheet having a thickness of 200 μm.

On the surface of the colored polycarbonate resin film, an acrylic resin film having a thickness of 50 μm (“Sanduren 007” manufactured by Kanegafuchi Chemical Industry Co., Ltd.) was used at 200 ° C.
After being laminated by a thermal bonding method using a pair of heat rolls, a polycarbonate resin is in contact with the mold surface, and a triangular pyramidal retroreflective element is used on the surface of the mold. Polycarbonate resin in which compression molding is performed under a molding pressure of 50 kg / cm ^{2 and} the resin sheet is taken out after cooling to 30 ° C. under pressure and a large number of triangular pyramidal retroreflective elements are arranged on the surface in a close-packed state. To obtain a fluorescent triangular pyramid type cube-corner retroreflective sheet.

On the other hand, a 38 μm thick white polyethylene terephthalate film manufactured by Mitsubishi Kagaku Polyester Film Co., Ltd. was coated with a polyester resin hot melt adhesive “Vylon GA2310” manufactured by Toyobo Co., Ltd. to a thickness of 35 μm by an extrusion method. Coating and laminating was performed to prepare a binder laminating support layer film.

The triangular-pyramidal cube-corner type retroreflective sheet and the binder laminated support layer film are passed between a mold roll having a mesh-like projection and a silicon roll to form a hermetically sealed red-orange fluorescent cube. A corner type retroreflective sheet was obtained.

In Example 1, the "deep groove type element" described later was used.

Example 2 A hermetically sealed red-orange fluorescent retroreflective sheet was obtained in the same manner as in Example 1 except that the "deep groove type asymmetric element" described later was used.

Example 3 Instead of the benzopyran-based fluorescent colorant used in Example 1
And in [Chemical 3], Z ₁-R₁Is N and Z_Two-R_Two,
Z_Three-R_Three, Z_Four-R_FourIs CH and R₅~ R₈
Is a methyl group, and both X and Y are oxygen coumarins.
Same as Example 1 except that 0.1 part of the fluorescent coloring agent is used
A hermetically sealed red-orange fluorescent retroreflective sheet was obtained.

Example 4 A hermetically sealed red-orange fluorescent retroreflective sheet was obtained in the same manner as in Example 3 except that the "deep groove type asymmetric element" described later was used.

Example 5 Instead of using 0.1 part by weight of the benzopyran-based fluorescent colorant in Example 1, R ₁ and R ₂ are both methyl groups and Ar ₁ and Ar ₂ are both C in [Chemical Formula 4]. ₆ H ₄ N (CH
₃ ) A hermetically sealed red-orange fluorescent retroreflective sheet was obtained in the same manner as in Example 1 except that 0.1 part of the fluorescent diketopyrrolopyrrole of ₂ ) was used.

Example 6 A vapor-deposited red-orange fluorescent retroreflective sheet was obtained in the same manner as in Example 5 except that the “deposited deep groove type asymmetric element” described later was used.

Example 7 A red-orange fluorescent retroreflective sheet was obtained in the same manner as in Example 1 except that the "symmetrical element having three grooves having the same depth" described below was used. It was

A deep groove type asymmetric element will be described.

On a brass plate of 100 mm square whose surface was cut flat, a diamond bite having a tip angle of 71.52 ° was used to repeat V-shaped grooves in the y and z directions at a repeating pitch of 210.88 μm. The depth of the V-shaped groove is 100 μm, and the intersection angle of the V-shaped groove in the y direction and the z direction is 58.76.
A large number of V-shaped parallel groove groups having symmetrical y-direction and z-direction cross-sections were cut by a fly-cutting method in a repeating pattern so that the cross-section became 0 °.

Thereafter, the V-shaped groove in the x direction was formed by using a diamond bite having a tip angle of 68.53 °, the repeating pitch of the V-shaped groove was 214.92 μm, and the depth of the V-shaped groove was 115 μm. And a V-shaped parallel groove which is parallel to a straight line connecting two intersections of the y-direction groove and the z-direction groove, and has a symmetrical cross-sectional shape in the x-direction so that the offset amount from the straight line is 11 μm. The group was cut in a repeating pattern to form a mother board in which a large number of convex triangular pyramidal cube corner element groups were arranged in a close-packed shape on a brass plate.

The height (hx ₁ ) from the apex (H ₁ ) to the bottom surface (Sx-Sx ′) of the pair of triangular-pyramidal retroreflective elements thus formed is 115 μm, and the height from the apex (H ₂ ) to the bottom surface is The height (hx ₂ ) to (Sx−Sx ′) is 100 μm, and the height (hyz ₁ ) from the vertex (H ₁ ) to the bottom surface (SS ′) is 100 μm, and the height (H ₂ ) is 100 μm. ) To bottom (S
The height (hyz ₂ ) to −S ′) was 85 μm. The triangular pyramidal retroreflective element had an optical axis tilt angle (θ) of + 1 °, and the apex angles of the side surfaces forming the reflective element were 90 °.

A deep groove type element will be described.

In the deep groove type asymmetric element described above,
A matrix was formed by cutting in the same manner as the deep groove type asymmetric element except that no offset was provided.

The height (hx ₁ ) from the vertex (H ₁ ) to the bottom surface (Sx-Sx ′) of the pair of triangular pyramidal retroreflective elements thus formed was 115 μm, and the height from the vertex (H ₂ ) to the bottom surface was The height (hx ₂ ) to (Sx−Sx ′) is 100 μm, and the height (hyz ₁ ) from the vertex (H ₁ ) to the bottom surface (SS ′) is 100 μm, and the height (H ₂ ) is 100 μm. ) To bottom (S
The height (hyz ₂ ) up to −S ′) was 100 μm. The triangular pyramidal retroreflective element had an optical axis tilt angle (θ) of + 1 °, and the apex angles of the side surfaces forming the reflective element were 90 °.

A vapor deposition type deep groove type asymmetric element will be described.

The aforesaid deep groove type asymmetric element comprises a heating device capable of melting aluminum with an electric heater in a graphite crucible installed in a vacuum container capable of maintaining a vacuum degree of about 9 × 10 ⁻⁴ mmHg. It was installed in a vacuum vapor deposition device. In the graphite crucible, pure aluminum pellets with a purity of 99.99% or more and granular metallic titanium are in a weight ratio of 100: 1.
The vapor deposition was carried out at an alternating voltage of 350 V and a current of 115 to 120 A, and vaporized aluminum atoms were vapor-deposited using the three reflection side surfaces of the device as specular reflection layers. At this time, the thickness of the aluminum vapor deposition film was 1100Å.

A symmetric element in which three grooves have the same depth will be described.

A diamond plate having a tip angle of 71.52 ° was used on a brass plate of 100 mm square whose surface was flatly cut, and the repeating pitch of V-shaped grooves in the y and z directions was 210.88 μm. The depth of the V-shaped groove is 100 μm, and the intersection angle of the V-shaped groove in the y direction and the z direction is 58.76.
A large number of V-shaped parallel groove groups having symmetrical y-direction and z-direction cross-sections were cut by a fly-cutting method in a repeating pattern so that the cross-section became 0 °.

After that, the V-shaped groove in the x direction was formed by using a diamond cutting tool having a tip angle of 68.53 °, the V-shaped groove had a repeating pitch of 214.92 μm, and the V-shaped groove had a depth of 100 μm. The V-shaped parallel groove group was cut in a repeating pattern to form a mother plate in which a large number of convex pyramidal cube-corner element groups were arranged on a brass plate in a close-packed manner.

Trigonal Pyramidal Retroreflection Formed in this Way
Vertex of element pair (H_1,H_Two) To the bottom (Sx-S
height up to x ') (hx₁, Hx_Two) Is 100 μm, the top
(H₁, H _Two) To the bottom surface (S-S ') (hy
z₁, Hyz₂) Was 100 μm. This triangular-pyramidal recursive anti
The optical axis tilt angle (θ) of the reflecting element is + 1 °, and the reflecting element
The apex angles of the side faces constituting the above were all 90 °.

Comparative Example 1 A commercially available fluorescent cube-corner type retroreflective sheet "Diamond Grade # 3924" (fluorescent orange) manufactured by Sumitomo 3M Co., Ltd. was prepared as a comparative example. The color clarity and weather resistance of the above fluorescent cube-corner retroreflective sheets were compared by the following method.

Comparative Example 2 Instead of the coumarin-based and benzopyran-based fluorescent colorants used in Example 1, 0.1 parts by weight of a known dye, namely Kayaset Flavine FG manufactured by Nippon Kayaku Co., Ltd. and Kayaset SF-4G 0 were used. A hermetically sealed red-orange fluorescent retroreflective sheet was obtained in the same manner as in Example 1 except that 1 part by weight was used.

<Measurement of Color> From the above reflection spectrum, tristimulus values (X, Y, Z) and chromaticity were measured by a color measurement method based on the spectrocolorimetric method defined in JIS Z8722-1994 of Japanese Industrial Standards. The coordinates (x, y, z) were determined. At this time, standard light D65 and viewing angle of 2 degrees were adopted.

<Evaluation of Weather Resistance> An Atlas Weathermate Ci65A type manufactured by Toyo Seiki Co., Ltd. equipped with a 6.5 kw xenon lamp was used to expose the evaluation sample for 3,000 hours, and the color before and after the test was measured. Was visually observed and the following graded evaluation was performed. AAA: A slight change in color and fluorescence. AA: The change in color is small, but the fluorescent sensation disappears. A: The fluorescent tone remains, but the color tone changes. B: A change in color and fluorescence is seen. C: The color is faded and whitened. Table 1 shows the color measurement values and the weather resistance evaluation results of the fluorescent cube-corner retroreflective sheets of the above Examples and Comparative Examples.

[0146]

[Table 1]

Table 2 shows the values obtained by measuring the retroreflective coefficient (the unit of the reflection luminance is cd / lx · m ² ) for the triangular pyramidal cube-corner retroreflective sheets of the above Examples and Comparative Examples. It was

The measurement of the retroreflective coefficient is based on Japanese Industrial Standard JIS
Z8714-1995: Retroreflector-Optical characteristics-Measurement based on the photometric measurement method specified in the measurement method, and the combination of the observation angle and the incident angle is 0.2 ° / 5 °,
It was measured as 0.2 ° / 15 °, 0.2 ° / 30 ° and 0.33 ° / 5 ° 1.0 ° / 5 °.

[0149]

[Table 2]

As shown in Tables 1 and 2, by combining the fluorescent colorant used in the present invention with a specific reflection sheet, a fluorescent retroreflective sheet having excellent fluorescence, light resistance and luminance characteristics can be obtained. Was obtained.

[0151]

[Brief description of drawings]

FIG. 1 is a sectional view of a triangular-pyramidal cube-corner retroreflective sheet of the present invention.

FIG. 2 is a sectional view of a vapor deposition type triangular pyramid cube-corner retroreflective sheet of the present invention.

FIG. 3 is a plan view and a sectional view of a triangular-pyramidal cube-corner retroreflective element of the present invention.

4 is a plan view and a sectional view of an enlarged view of the device of FIG.

FIG. 5 is a plan view of a triangular-pyramidal cube-corner retroreflective element of the present invention.

6 is a plan view and a sectional view of an enlarged view of the device of FIG.

[0152]

[Explanation of symbols]

1 Surface protection layer 2 printing layers 3 Support layer 4 Retroreflective element layer 5 3 and 4 together 6 air layer 7 Binder layer 8 Support layer 9 Adhesive layer 10 Release agent layer 11 Light incident direction 12 Specular reflection layer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2D064 BA03 CA03 EB25 EB31 EB35                 2H042 EA04 EA13 EA14 EA17 EA20                       EA21                 3D024 CA01 CA15                 5C096 AA01 BA03 CA03 CB06 CE03                       FA03 FA07

Claims (12)

[Claims] 1. At least a surface protective layer and a retroreflective element layer
In the retroreflective sheet consisting of
The element layer and the layer between the surface protection layer and the retroreflective element layer are small.
At least one layer has formula (1) [Chemical 1] (In the formula, R¹as well as²Are independently hydrogen atom or carbon number
1 to 4 alkyl groups are shown. ) Bear
Phosphorus compound or formula (2) [Chemical 2] (In the formula, R₁~ R_FourAre each a hydrogen atom or 1 to 4 carbon atoms
Represents an alkyl group of R,₅May have a substituent
Represents an alkyl group, an aryl group or a heteroaryl group,
X is -CO- or -SO_TwoRepresents a group. )
Nzopyran compound or formula (3) [Chemical 3] [In the formula, Z₁, Z_Two, Z_ThreeAnd Z_FourIs a nitrogen atom or carbon
Represents an atom, Z₁~ Z_FourAt least one of the
Represent, R₁, R_Two, R_ThreeAnd R_FourIs attached to a carbon atom
, Each independently a hydrogen atom, a halogen atom,
Group, nitro group, amino group, dialkylamino group, dia
Reel amino group, hydroxyl group, alkoxy group, aryloxy
Si group, mercapto group, alkylthio group, arylthio group
Group, silyl group, siloxy group, alkyl group or aryl
Represents a group, even if two adjacent groups combine to form a ring
Good. R₁, R_Two, R_ThreeAnd R_FourIs bound to the nitrogen atom
Indicates that it is not substituted. R₅, R₆, R₇And R₈
Each independently represents an alkyl group having 1 to 6 carbon atoms. X is an acid
Elemental atom, sulfur atom, -NH-, or -NR₉-In
Yes, Y is = O, = NH or = NR₁₀Is.
(R₉And R₁₀Is an alkyl group having 6 or less carbon atoms, or
Represents a cycloalkyl group. )] Coumarin system
Compound or formula (4) [Chemical 4] [In the formula, R₁And R_TwoIndependently of one another, C₁-C₂₅
Alkyl, allyl (this is C₁-C_ThreeAlkyl is Ar
_ThreeCan be substituted 1 to 3 times), -CR_Three
R_Four-(CH_Two)_m-Ar_Three(Where R_ThreeAnd R
_FourIndependently of one another, hydrogen or C₁-C_FourAlkyl
Or phenyl (which means C ₁-C_ThreeAl
Can be substituted 1-3 times with kills)
And Ar_ThreeIs phenyl, or 1- or 2-naphthyl
(This is C₁-C₈Alkyl, C₁-C₈Arcoki
Si, halogen or phenyl (this is C₁-C₈A
Rukiru, C₁-C₈Substituted 1-3 times with alkoxy
Can be substituted 1 to 3 times with
M) means 0, 1, 2, 3 or 4,
Here, C₁-C₂₅Alkyl or -CR_ThreeR_Four-(C
H_Two)_m-Ar_Three, Preferably C₁-C₂₅Alkyl
Is a functional group capable of increasing the solubility in water, for example,
Tertiary amino group, -SO_Three ⁻Or PO_Four ^2-Replaced by
Can be Ar₁And Ar_TwoAre independent of each other
And the following formula: [Chemical 5] In the above formula, R₅Is C₁-C₆Archi
Le, -NR₈R₉, -OR ₁₀, -S (O)_nR₈,-
Se (O)_nR₈, Or phenyl (this is C₁-C ₈A
Rukiru or C₁-C₈Substituted with alkoxy 1-3 times
Can be)), where R₈And R
₉Independently of each other, hydrogen, C₁-C₂₅Alkyl, C
₅-C₁₂Cycloalkyl, -CR_ThreeR_Four-(CH_Two)
m-ph, R ₁₀(Where R₁₀Is C₆-C₂₄Ants
Group), or a saturated group containing 5 to 7 ring atoms.
Or an unsaturated heterocyclic group (where the ring is a carbon atom and a nitrogen,
1 to 3 hetero atoms selected from the group consisting of oxygen and sulfur
Atom) and wherein ph, aryl and
The heterocyclic group is C₁-C₈Alkyl, C₁-C₈Arcoki
It may be substituted one or three times with Si or halogen.
Can or R₈And R₉Is -C (O) R
₁₁(Where R₁₁Is C₁-C₂₅Alkyl, C₅
-C₁₂Cycloalkyl, R₁₀, -OR₁₂Or
-NR_ThirteenR₁₄(Where R₁₂, R_ThirteenAnd R₁₄
Is C₁-C₂₅Alkyl, C₅-C₁₂Cycloalk
Le, C₆-C₂₄Means aryl) means)
Or saturated or unsaturated compounds containing 5 to 7 ring atoms
A cyclic ring group (where the ring is a carbon atom and nitrogen, oxygen and sulfur
Consisting of 1 to 3 heteroatoms selected from the group consisting of
), Wherein the aryl and heterocyclic groups are C
₁-C₈Alkyl or C₁-C₈1 to 1 with alkoxy
It can be substituted 3 times or -NR₈R
₉Is R₈And R₉Together, tetramethylene,
Pentamethylene, -CH_Two-CH_Two-O-CH_Two-CH
_Two-Or-CH_Two-CH_Two-NR₅-CH_Two-CH
_Two-, Preferably -CH_Two-CH_Two-O-CH_Two-C
H_TwoMeans a 5- or 6-membered heterocyclic group, which means-, and n is
Means 0, 1, 2, or 3, and where R₆as well as
R₇Independently of one another, hydrogen or R₅Means the same
Sometimes does not mean hydrogen, preferably R₆Is R₅Means
And R₇Means hydrogen, and the fluorescent diketopi represented by
A small number of fluorescent colorants selected from the group consisting of loropyrrole
Fluorescent retroreflection characterized by containing at least one kind
Sheet. 2. The fluorescent retroreflective sheet according to claim 1, wherein the retroreflective element layer comprises a triangular-pyramidal cube-corner retroreflective element. 3. A large number of pairs of triangular-pyramidal retroreflective elements, one on the other.
The side facing (c ₁Surface, c_TwoBottom shared by faces)
From the bottom surface (Sx-Sx ') including (x, x, ...)
Vertex of pyramidal retroreflective element (H₁) Up to hx₁When
Then, one side surface (a₁
Surface, a_TwoBottom surface (z, z) and the other side surface (b)
₁Surface, b_TwoCommon to include both sides (y, y) of
From the bottom surface (S-S ') to the vertex (H₁) Up to hyz1
And then hx₁Is hyz₁Substantially larger triangular pyramid
The fluorescence according to claim 2, which is a reflective element.
Retroreflective sheet. 4. A retroreflective element has three side surfaces (a ₁ surface, b ₁ surface, c ₁₎ intersecting at substantially right angles with each other by intersecting V-shaped grooves having substantially symmetrical cross sections. Surface; a ₂
Surface, b ₂ surface, c ₂ surface ...), and a pair of triangular pyramid-shaped cube-corner retroreflective elements that are separated from each other so as to project to one side on a common bottom surface (SS ′). The pair of triangular-pyramidal retroreflective elements are arranged in the closest packing state, and the side surfaces (c ₁ surface, c ₂ surface) facing each other share one base (x) to form a pair. , The bottom surface (S
-S ') is the base (z, z) of _one side surface (a ₁ surface, a ₂ surface) and the other side surface (b ₁ surface, b ₂ surface) of the pair of triangular-pyramidal retroreflective elements. The pair of triangular-pyramidal retroreflective elements, which are common planes including both the bases (y, y) and share the base (x), have side surfaces (c ₁ surface, c ₂ surface) facing each other. Have different shapes, and the heights from the bottom surface (S-S ') to the vertices are different from each other, The fluorescent retroreflective sheet according to claim 2 or 3, wherein. 5. An air layer hermetically sealed by a mesh-shaped joint between the retroreflective element and the binder layer of the retroreflective sheet. Fluorescent retroreflective sheet. 6. The fluorescent retroreflective sheet according to any one of claims 2 to 4, wherein the retroreflective element of the retroreflective sheet is provided with a specular reflective layer made of metal. 7. At least one layer closer to the incident light side than the enclosed air layer comprises 0.01 to 0.5 PHR of the fluorescent colorant.
The fluorescent retroreflective sheet according to any one of claims 1 to 6, which is contained within the range of. 8. The fluorescent retroreflective film according to claim 1, wherein the layer containing a fluorescent colorant further contains a piperidine type hindered amine light stabilizer having a tertiary amine structure having a molecular weight of 600 or more. Sheet. 9. The fluorescent retroreflective sheet according to claim 8, wherein the layer containing a fluorescent colorant contains a piperidine type hindered amine light stabilizer within a range of 0 to 1 PHR. 10. The fluorescent retroreflective sheet according to claim 1, wherein the retroreflective layer and / or the surface protective layer and / or the layer containing a fluorescent colorant contains an ultraviolet absorber. 11. The fluorescent retroreflective sheet according to claim 10, wherein the ultraviolet absorber is a benzotriazole-based or benzophenone-based ultraviolet absorber. 12. The fluorescent retroreflective sheet according to claim 1, wherein the resin constituting the retroreflective element layer is polycarbonate resin, (meth) acrylic resin, vinyl chloride resin or urethane resin.