SE468946B - Road marking which is fluorescent when irradiated with UVA light - Google Patents

Abstract

A road marking in the form of thermoplastic, paint powder or paint with solvent and/or water. It is intended to be used as a marking on roads, streets, jetties and open spaces. To make the road marking visible in the darkness, even when covered by water, it is composed of material, glass, pigments and binders which are fluorescent when irradiated with UVA light.

Description

46 CEO 2 A 'road marking' that 'is covered by a' water film is not visible when driving in the dark.

Compared with dry road surface in daylight, traffic accidents increase practically by a factor of 2 in dry road surface and in the dark, and further by a factor of 2 in wet road surface and darkness.

Significant gains in life and materials can therefore be achieved if one can increase the visibility of road markings at dry road surface, darkness and low beam.

A sensational advance in the fight against traffic fatalities would be achieved if road markings could be made visible in the dark even if they are covered by water.

Many attempts have been made to achieve this. Raised reflective elements have been built into the Road Marking. The road marking has been done in the form of clicks, slats, grid patterns, etc.

The purpose of this has been for the rainwater to run off the profile and for the marking to break through the reflective water film.

Some improvements have been achieved, but the marking still has limited visibility.

In addition, certain inconveniences are associated with this marking technology, including a noise that is disturbing to the surroundings when a vehicle passes the marking.

The present invention provides a road marking which satisfies the desire for a road marking which is also fully visible under a reflective water film in the dark.

The present invention thus relates to a road marking intended to be placed on roads, streets, bridges and places where the lighting on vehicles and / or roads, streets, bridges and places has been supplemented with UV headlights. Thereby 468 946 3 fluoresces the marking and becomes visible even under a reflective water film. Increased visibility is also achieved in fog and snow smoke.

The road markings include white pigment, binder and doped glass, all of which fluoresce individually when exposed to UV radiation within the medically acceptable range of UVA 315-400 nanometers.

It is known that so-called optical brighteners based on Stilben, Cumarin, Pyrazoline and benzene-based heterocyclic substances fluoresce within the mentioned wavelength range.

Through small additions to road marking paint, you can give the paint the desired effect for a short time.

When the Road Marking has received a thin layer of traffic dirt, the effect ceases.

In road marking of the thermoplastic type, the above-mentioned fluorescent substances change due to the high application temperature of the road marking, approximately 200 ° C and the expected effect is absent.

The road marking according to the invention consists of a thermoplastic paint which is applied with a melting equipment, or of a paint which is applied in powder form and sintered together after, or in connection with the application, or a paint with solvent or water.

The road marking according to the invention is composed of material which fluoresces when exposed to UV radiation within the medically acceptable path length range UVA.

A fairly large amount of material fluoresces when illuminated with ultraviolet light throughout the UV range. Most materials fluoresce in different colors. êöß 146 4 There are few materials that fluoresce when exposed to UVA light.

Of the materials that fluoresce when illuminated with UVA light, few fluoresce in white or white-yellow.

Typical materials in a road marking are glass, pigment and binder.

Fluorescence occurs in a color center in, for example, glass in that it absorbs a certain amount of energy E in the short-wave range during UV radiation. The paint centre's energy Electricity will thus increase.

E1 + E = Ez but at the same time becomes unstable in this higher energy state and tries to get rid of the excess energy to the environment and return to its original state. The excess is emitted as radiation fluorescence.

The present invention relates to a method of applying the fluorescent effect obtainable from glass. The glassy material can either be in the form of beads or as crushed and fractionated material.

The base glass is of the silicon-lime, soda glass or glass type with additives of lead, titanium, boron, phosphorus or barium oxide that can affect the refractive index of the glass.

As base glass, waste glass, colored or uncoloured from bottle, can or flat glass production can also be used.

The base glass mass, whether based on quantity or waste glass as above, is placed in a molten state with substances that give fluorescence effects in the glass within the 320-400 nanometer range.

Examples of such substances are cerium, vanadium, manganese, cobalt, europium, samarium. 468 946 5 A preferred additive is cerium which gives glass which fluoresces in White - blue and white.

For yellow markings, additives of vanadium and manganese are suitable as they give glasses that fluoresce in yellow.

Titanium dioxide is usually included in Road Markings as a white pigment to meet the requirement for whiteness and visibility in daylight or visible light. Titanium dioxide does not fluoresce.

Zinc oxide is a white pigment that fluoresces in white-yellow when exposed to UVA radiation, and at the same time has such a covering ability that it makes the road markings white in visible light.

The binder in a road marking consists of resin, plasticizer and thermoplastic.

The binder can be composed so that it fluoresces in white-yellow upon UVA irradiation.

According to a preferred embodiment, the binder consists of 70-80% resin, 12-20% plasticizer and 6-12% thermoplastic.

Examples of resins are Piccopale 100 from Hercules and Bevilite 62-107 from Bergvik.

Examples of plasticizers are mineral oils and examples of thermoelastics are ethylene vinyl acetate copolymers.

Road markings are exposed to heavy pollution from traffic. Through abrasion and water rinsing during rainy periods, a satisfactory visibility is maintained balanced against the desire for good durability against abrasion.

It is important that materials included in the road marking fluoresce during UVA radiation. Materials that do not fluoresce appear after pollution from traffic as absorbents for UVA radiation that prevents even fluorescent materials.

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The present invention thus consists of a series of discoveries which fulfill the initially stated desire to make road markings visible in the dark even if they are covered by water.

During dusk and dawn, natural light contains a large proportion of ultraviolet light. This means that the visibility of the marking is significantly improved compared to conventional marking.

According to. announcements from the 'Road and Traffic Institute', there are plans to equip vehicles and road lighting with headlights, which emit UVA radiation.

Lamps for this purpose are already available, as are specially designed headlights.

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Claims (2)

7,468,946 Patent claims Road marking in the form of thermoplastic, toner or paint with solvents and / or water intended for use as marking on roads, streets, bridges and places, which road marking comprises glass particles, pigments and binders which fluoresce when irradiated with UVA light, characterized in that the glass particles comprise glass doped with cerium, that the pigment comprises zinc oxide, and that the binder comprises 70-80% by weight of resin, 12-20% by weight of plasticizer and 6-12% by weight of thermoelastics. Road marking according to claim 1, characterized in that the proportion of glass particles in the marking amounts to 40-70% by weight, that the proportion of pigments amounts to 20-30% by weight, and that the proportion of binder amounts to 15-25% by weight.