US 3523856 A
Description (OCR text may contain errors)
L. L; YAEGER WARNING SIGN Filed Oct. 6, 1966 3,523,856 WARNING SIGN Luther L. Yaeger, Houston, Tex., assignor to Griifolyn Company, Inc., Houston, Tex., a corporation of Delaware Filed Oct. 6, 1966, Ser. No. 584,788 Int. Cl. B44f 1/02 U.S. Cl. 161-4 Claims ABSTRACT OF THE DISCLOSURE A day-night flexible foldable warning sign of extreme flexural fatigue resistance and excellent efiiciency has a reflecting metal light barrier layer and a fiber reinforced resilient adhesive layer, and on one side a plastic film or layer containing a fluorescent dye, on the other side a transparent colored plastic film or layer. Thus incident light will be reflected in a conspicuous manner and at a conspicuous Wave length. 1
This invention relates to warning signs, and particularly to low cost, extremely rugged warning signs for use both at day and night.
Heretofore, warning signs have been made by use ofinterchangeable adhesive backed fluorescent pigmented or glass beaded coatings or films, or from metals or other rigid materials coated with such substances. Printed warning signs of cardboard or plastics have either been rigid so as to be inconvenient to handle, or they have been tearable or otherwise lacking in ruggedness, so that their use was lacking in dependability in strong winds and generally in that type of weather conditions when warning is particularly important. Significantly, flexible or collapsible signs of prior art have been greatly suffering from a lack of fatigue resistance, which made them almost useless under conditions when strong winds might cause flutter in their flexible parts.
An object of the present invention is a reversible, flexible warning sign of outstanding fatigue resistance.
Another object is a dual purpose day-night warning or advertising sign.
Another object is a minimum-space, minimum-weight warning sign.
Further objects will become apparent as the following detailed description proceeds.
In accordance with my invention, I employ a laminate of at least two films, separated by a fatigue controlling interlayer which comprises a permanently transposable tacky or high hysteresis substance, in conjunction with a fibrous containing network to hold this in place and to contribute to fatigue strength and resistance of the structure, the film on one side containing an opaque, fluorescent pigment highly conspicuous in daylight, such as the proprietary products named Hi-Viz #13 Orange or #34 Red produced by Lawter Chemical Corp. or Day- Glo Fire Orange or Rocket Red produced by Switzer Bros, Inc., and on the other side a transparent film con taining dissolved or transparently dispersed therein a coloring substance, and further as a backing of this latter film a reflecting layer of a metal or equivalent. The reflective film can also be turbid or even opaque if the metallized or equivalent reflectant side is on the outer face and coated with a clear (transparent) but colored lacquer. The fluorescent pigment may also be dispersed in the laminating adhesive and transparent film used on the non-reflective daylight Warning face.
In further describing the invention, I am referring to the drawings which are presented to help explain the invention and not in any sense of limitation, FIG. 1 is a cross section, FIG. 2 is a view from above, FIGS. 3 and 4 are United States Patent Office 3,523,856 Patented Aug. 11, 1970 perspective views of the finished article and the mode of assembling it.
In accordance with my invention, I employ a reversible Warning sign which, viewed from one side 2 presents an opaque, highly reflectant fluorescent dye extremely visible under daylight conditions and similar to the fluorescent color strips used, for instance, on airplanes to make them easily spotted by traffic control and by other airplanes from a long distance. The other side of the article presents a reflected colored light at night, which is obtained by metallizing 3 of the back side of a transparent colored plastic 1 or metallizing the front side and coating with a transparent, colored lacquer.
Reinforcing means 4 are provided in order to give the article the required strength and tear resistance, which will permit its continued utility for a long period of time and of rough handling, and particularly to keep in place the anti-fatigue intermediate layer, hereafter referred to as the interlayer. This interlayer greatly enhances the fatigue resistance of the sheet by preventing creep of its component, the intermediate buffer and cushion layer which further ensures permanence of the thin metal coating by cushioning.
' EXAMPLE 1 Referring to FIGS. 1-4, reference numeral 1 represents a sheet of low density polyethylene in which, prior to extrusion, a fluorescent pigment nonsoluble in polyethylene was dispersed. To prepare an article similar to that shown in the figures, this sheet was spread, temporarily fastened to a flat surface (not shown) and sprayed with a solution 3 of 20% crude rubber and 15% gum rosin in 65% of a blend of equal parts by volume of hexane and orthoxylene and then allowed to dry overnight. The following day, 200 denier nylon fibers 4 are placed in a diamond pattern, spaced A" apart, in two parallel layers forming angles with each other and 45 angles with the sides of the plastic. A sheet of polyethylene, vacuum evaporation coated with aluminum and having /2 rhodamine dye dissolved in the plastic 2, was then applied onto this assembly so that the metallized side 4-was covered by the other sheet 2. The resultant article-was in dimension 3 ft. square. On the Schopper bending endurance tester test, this structure withstood 1,300,000 bending cycles component polyethylene film of the same thickness as the aggregate (6 mil) failed before 200,000 bends. The aluminum coating likewise remained functional after completion of the bending test.
EXAMPLE 2 Parts Methyl acrylate-butyl acrylate interpolymer, (4:1
molar ratio) polymerized in 80% t0luol-20% isopropyl acetate to give 43% solids with org. M.W.
of 9,000 Glycerol ester of hydrogenated Wood rosin (Acid No.
8) 55 Petroleum distillate (boiling range 55-92. C.)
The above composition was applied to the aluminum coated side of the latter sheet. The composition was allowed to dry in air. Two layers of parallel 400 denier polyethylene glycol terephthalate fibers were laid down on the polypropylene film, fibers spaced /2" from each other and forming 90 angles with each other so as to 3 create a square pattern, and were rolled down onto it using a Teflon roller. The aluminum coated film was then rolled down onto it, the coated side down.
The resultant article was very rugged and resistant, particularly to fatigue effects such as those caused by winds, and conspicuously visible on one side in daylight, on the other side in reflected light.
EXAMPLE 3 A polyvinyl chloride film, plasticized with dioctyl phthalate (20%) and pigmented with of a fluorescent dye known as Day-G Fire Orange was coated with a 1 mil layer of the following composition and allowed to dry:
Parts Latex of ethyl acrylate with 10% copolymerized 2-ethylhexyl acrylate (49.2% solids) 80 Pentaerythritol ester of refined tall oil rosin, (softening pt. 122 C., Acid No. 17) emulsified with 2% potassium oleate, pH 7.8, 55% solids 67 Phenyl salicylate 0.2 Ammonium caseinate (20% in water) 14 Water, deionized 140 These are particularly applicable to polyethylene and polypropylene films.
Separately, an aluminum vacuum coated sheet of polyethylene glycol terephthalate was coated on the nonmetallized side with the same adhesive as the polyvinyl chloride film. A grid of 200 denier nylon fibers was then placed over the adhesive coated side of the first above-mentioned film, and the lamination completed by rolling over it the other film, the coated sides of said films facing each other.
The structure above described offers surprising advantages not anticipated on the basis of the structure. For example, the use of the fibers in conjunction with the elastomeric adhesive, results in a high fatigue strength coupled with extremely high tear strength. While I have not determined in detail the mathematics of these stressstrength characteristics, it is my belief that the presence of the fibers in the stress pattern distribution at the same time introduces a cushioning effect in the intermediate or bonding layer adjacent to the metalized film, which protects the metal layer of this film from such ruptures as would otherwise take place on rough handling. Conversely, the presence of the fibers which are movable to some extent within the adhesives, have the effect of causing a rolling rather than a rubbing action in contact with the metalized layer which also tends to preserve this so that it will not rupture or become cracky and ineflicient after the article has been exposed in the open and may have been fluttering in a strong wind or in the air current engendered by vehicle speed when it is attached to a moving vehicle.
The product of this invention is characterized particularly by the presence of the one layer of an opaque dispersion of a fluorescent pigment very visible in daylight on one side, a transparent layer of dye dissolved in the plastic or dispersed so finely that it is in effect transparent, a layer of metal so disposed as to reflect lights incident from the side of the colored transparent plastics, and between the plastic films an anti-fatigue composite layer comprising both a flexible elastomeric or high viscous plastic composition, in which are embedded fibers which form a system adapted to distribute and mitigate stresses and strains and to hold in place the movable anti-fatigue layer which bonds the two film systems together.
In its broad element, the invention comprises means of non-transparently carrying fluorescent pigments adapted to be very highly visible in daylight, means for reflecting colored light at night, combined by stress and fatigue distributing means including a resilient or high hysteresis matrix material and a system of stress absorbent fibers positioned within this layer.
Suitably the plastics used as carrier for the pigment and for the dyestuif and for the metal layers can all be identical, but they may also be different. They can be hydrocarbon resins such as styrene, polyethylene, polypropylene; they can be vinyls; they can also be cellulosic or polyester resins such as the polydiethylene glycol terephthalate; they can be polyurethane resins or polyfluoro alkyl or alkylene resins; in fact, they can be any polymer or polymer combination which is substantially transparent in itself and permits incorporation of the fluorescent pigment and of the colored dyestuff as disclosed above.
For metalizing I prefer to use a vacuum metal deposit, a sprayed deposit or a rolled-on aluminum flake deposit, preferably of a conveniently deposited metal such as aluminum or gold, but with the possibility of using any highly reflectant metallic surface that can be applied in any practical manner.
As for the fibers, I prefer to use fibers of the above, or other suitable plastics, which have a potential elongation of at least 20% and up to 800%; however, more or less extensible fibers can also be used although they are not preferred. From the standpoint of minimizing fatigue, I prefer to use fibers or fiber bundles having roughly circular cross sections although this is not necessary for the use of the invention, and to use these in non-woven patterns involving groups of parallel fibers.
As resilient or high hysteresis energy absorbing mate rials in the interlayer and held or anchored by the stress resisting and distributing fibers, I may use generally elastic or deformable plastics rigid enough to eifect considerable energy absorption, yet soft enough to yield before the plastic or metal films adjoining it are broken, and thus cushioning these from impact and particularly fatigue effects. In addition to the rubber resin composition shown in the example, I may use, for example, solid polyfluoroethylenes having a tenacity less than the tenacity of the adjoining films, either in itself or because of the incorporation therein of lower polymers to soften it, or of other compatible weakening agents, or of incompatible weakening agents intermixed with it intimately. Similarly, I may employ other high hysteresis or resilient polymers analogously compounded, such as a polyvinyl chloride of molecular weight 200,000 softened by addition of 30% dioctyl phthalate, or of acetal resins such as polyvinyl butyral softened with 15% dioctyl phthalate and 10% diheptyl sebacate; or a polyurethane made by interaction of castor oil and the stoichiometrically equivalent quantity of a diisocyanate; or a reclaim rubber having softness 30 on the Shore scale, or a methyl methacrylate softened with 12% of polylauryl methacrylate and 4% diallyl sebacate; or a soft copolymer of high and low molecular methacrylates, or ethyl or ethyl-butyl acrylate and homologues, or generally any polymer having a molecular weight high enough to impart some body or high viscosity (preferably above 50,000 centipoise at 25 C.) but low enough to remain more bendable and/or deformable than an equal thickness of the adjoining film surfaces. Obviously this provides a wide range of selection of material; the choice will be governed by the selection of film and fiber component. The information provided will suffice to enable those skilled in the art to select one or several suitable interlayer materials for any given combination of films, fibers and conditions of anticipated use.
It is thus seen that the invention is broad in scope, and is not to be restricted excepting by the claims in which it is my intention to cover any novelty inherent in this invention as broadly as possible in view of prior art.
Having thus disclosed my invention, I claim:
1. A day-night flexible foldable warning sign, essentially consisting of an opaque light reflective metal layer having a thickness in the range of commercially produced non-transparent vacuum deposited coatings and lightweight flexible metal foils, on one side of the aforesaid metal layer bonded thereto a dispersion of a fluorescent coloring material in a substantially transparent adherent flexible foldable plastic; and on the other side of the said metal layer bonded thereto a substantially transparent flexible foldable plastic layer containing a transparent dye so as to color any incident light reflected back therethrough by the said metal layer, the said plastic layers having a thickness in the range of commercially produced plastic lacquer coatings and films, the said product being reinforced with non-woven plastic fibers in patterns involving groups of parallel fibers located between the said plastic sheets wherein two or more sets of fibers are arranged at intersecting angles.
2. The day-night warning sign of claim 1, the said stress-distributing fibers having elongation between 20% and 800% and being positioned at least about A inch spacing from each other, in nonwoven patterns involving groups of parallel fibers.
References Cited UNITED STATES PATENTS 2,939,200 6/1960 Ewing et al. 161-55 XR 3,290,203 12/1966 Antonson et al 161-4 JACOB H. STEINBERG, Primary Examiner U.S. Cl. X.R.