Stock material or miscellaneous articles – Structurally defined web or sheet – Including variation in thickness
Patent
1996-08-15
1998-06-02
Watkins, William
Stock material or miscellaneous articles
Structurally defined web or sheet
Including variation in thickness
428141, 428143, 428156, 428195, 428201, 428203, 428204, 428207, 428325, 428913, 428178, 359529, 359530, 359531, 359532, 359533, 359534, 359536, 40612, 40442, 40542, 40543, 40582, 2504611, 2504861, G02B 5122, G02B 5128
Patent
active
057596719
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a retroreflective sheeting which is useful for markings such as road signs, directional signs and construction signs; number plates on vehicles such as automobiles and motorcycles; safety goods such as safety cloths and survival equipment; and marking materials for signboards, vehicles, etc. More particularly, the invention relates to an ultraviolet luminescent retroreflective sheeting composed of a retroreflective region in which retroreflective elements are disposed and an ultraviolet luminescent region which emits light under ultraviolet radiation, said ultraviolet luminescent region containing a fluorescent agent which emits light under ultraviolet radiation and a resin component, and the luminance of said light being within a specific range.
Background Technology
Retroreflective sheetings which retroreflex light towards the light source are well known. Utilizing their excellent visibility at night due to the retroreflective property, the sheetings have been used in wide areas as above. For example, road signs, construction signs or the like using a retroreflective sheeting reflex light from a light source such as headlight of a running vehicle like automobile in the direction of the light source at night, i.e., in the direction of the running automobile, to provide excellent visibility to the driver of the vehicle who sees the sign. Thus the sheeting exhibits a very favorable property of whereby enabling transmission of accurate informations.
Whereas, since retroreflective sheetings in general reflex-reflect light from a light source toward the light source, they offer excellent visibility in the direction of the light source, but only markedly inferior visibility to the persons who are not in the direction of the light source. Furthermore, because of the property innate in retroreflective sheeting, as a light source on a vehicle like an automobile approaches a retroreflective sheeting-made sign, the divergence between the angle of incident light from the light source and that of the driver's observation increases, to substantially reduce the visibility. Besides, accompanying recent road system development and diversification in informations to be transmitted, amount of informations loaded on single directional sign is increasing, and when speed of a running vehicle is taken into consideration, it has become very difficult for a driver to read the necessary informations within an extremely short time during which he stays in the area wherefrom the retroreflective light is visible.
For those reasons, conventional type retroreflective sheetings having the retroreflective ability alone provide only insufficient visibility when they are put to the usages where more accurate information supply or higher advertising effect are required. In particular, high quality retroreflective sheeting, which is capable of offering always excellent visibility, even at night, for example, and even to persons who are located in the directions differing from that of the light source, has been strongly demanded.
Aiming at meeting this demand, various attempts have been made to improve visibility of retroreflective sheeting. For instance, JP-A-173008/1993 discloses an encapsulated lens-type retroreflective sheeting exhibiting, concurrently with retroreflectivity, long persistent phosphorescence, in which a transparent resin layer is used as a support layer and a layer of long persistent phosphorescent substance is provided on the back of the support layer (the surface opposite to the incident side). However, the luminous energy of the luminescent substance is low and besides, visibility-improving effect of this proposal is yet definitely insufficient, because according to the proposal the layer of long persistent phosphorescent substance is under that of the microspherical lens layer and, of the light emitted by the substance, mainly only the part which transmitted the spaces between the microspherical lenses is visible.
PCT International Publication WO 93/14422 discloses a photol
REFERENCES:
patent: 3830682 (1974-08-01), Rowland
patent: 4025674 (1977-05-01), Mizuochi
patent: 4250646 (1981-02-01), Trachtenberg
patent: 4424449 (1984-01-01), O'Brill
patent: 4555161 (1985-11-01), Rowland
patent: 4653864 (1987-03-01), Miyata
patent: 4656072 (1987-04-01), Coburn, Jr. et al.
patent: 4952023 (1990-08-01), Bradshaw et al.
patent: 5009019 (1991-04-01), Erlendsson et al.
patent: 5050327 (1991-09-01), Woltman
patent: 5085918 (1992-02-01), Rajan et al.
patent: 5223977 (1993-06-01), Bennett
patent: 5229882 (1993-07-01), Rowland
patent: 5237448 (1993-08-01), Spencer et al.
patent: 5272562 (1993-12-01), Coderre
patent: 5414947 (1995-05-01), Hjaltason
patent: 5478628 (1995-12-01), Billingsley et al.
patent: 5516227 (1996-05-01), Kozak et al.
Fushimi Hidenori
Hiromitsu Kiyohito
Tanaka Osamu
Nippon Carbide Kogyo Kabushiki Kaisha
Watkins William
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