GB2440915A

GB2440915A - Glow in the dark item with luminescent material in clear binder

Info

Publication number: GB2440915A
Application number: GB0616546A
Authority: GB
Inventors: Malcolm Roger Curzon Donald
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-08-19
Filing date: 2006-08-19
Publication date: 2008-02-20
Also published as: GB2441199A; GB0715620D0; GB0616546D0

Abstract

A photoluminescent substance is mixed with a transparent or translucent binder. The composition 3 is coated or laminated onto a substrate 2, possibly after being cast in a mould. Preferably wear resisting glass beads 4 are added to or sprinkled on the resinous binder. A colourless, translucent or transparent resin 5 may be applied onto the sprinkled glass beads 4, either before or after the underlying resin has been polymerised or crosslinked. The method produces illuminated decorative or informative items, handrails, stair treads, or building fittings on floors and walls which supplement emergency lighting.

Description

GLOW IN THE DARK ITEMS

This specification relates to photoluminescent materials and their use to provide visible illumination in the dark. The specification is primarily, but not exclusively, relevant to directing people towards exits in emergency situations.

Green emergency exit signs and direction signs are common features in public buildings, hotels, conference centres, etc. and are permanently illuminated by the emergency lighting systems so that, in the event of mains power failures, these should remain lighted.

However, it is not unknown for the emergency lighting to fail at this most critical of times.

Even when the emergency lighting works properly another problem can be when many people are hurrying towards an exit and each is casting a shadow in the limited light available so that it is difficult to see, for example, the first step of a flight of stairs. In such circumstances, it can take only a single person to stumble and fall for an orderly exodus to become a stampede and people to be trampled to death. Additionally, of course, people walking through the smoke could stumble over others, on their hands and knees, trying to avoid the higher-level smoke.

Clearly, the more emergency lights there are on any exit route, the better. In practice, however, the cost and capacity of battery I emergency power systems will restrict the number of lights that can be employed and, even the minimum legal limits, can still leave some areas of poorly illuminated. If power availability limits the number of lights, which can be provided, the question arises whether non-powered illumination can be provided to supplement the light available? In the worst possible case, when the emergency lighting fails completely, non-powered illumination would be the only option available.

Photoluminescent substances are known and can be used to supplement emergency lighting.

Thus, there is a need for means to supplement emergency lighting, particularly in critical areas, such as flights of stairs, etc. Ideally, this supplementary illumination should not rely on electrical power and be applicable at low levels, which might otherwise be in shadow.

1P1783 According to the invention, there is provided a method of making luminous items, comprising: i) providing a substrate; ii) affixing / applying a photoluminescent substance to the substrate to form a luminous item and iii) providing the luminous item for use; charactensed in that the photoluminescent substance is present within a translucent / transparent canier, which is fast / firmly bondable with the substrate and which protects the photoluminescent substance from regular wear and tear and accidental damage.

According to a first variation of the method of the invention, the substrate is an element attachable to a structural member.

According to a second variation of the method of the invention, the substrate is a structural member.

According to a third variation of the method of the invention, the carrier is a polymensabte resin.

According to a fourth variation of the method of the invention, the photoluminescent substance is intimately mixed with the carrier.

According to a fifth variation of the method of the invention, a layer of the carrier and photoluminescent substance is applied to the substrate.

According to a sixth variation of the method of the invention, particles of a translucent / transparent filler are applied to the un-polymerised carrier layer.

According to a seventh variation of the method of the invention, the un-polymensed carrier layer is polymerised so that the translucent / transparent filler particles applied thereto become permanently bonded therewith.

IP1 783 2 According to an eighth variation of the method of the invention, a translucent I transparent resin layer is applied to the translucent / transparent filler particles bonded to the polymensed camer layer.

According to a ninth variation of the method of the invention, the translucent I transparent resin layer is polymensed so that it forms a smooth external coating over the filler particles.

According to a tenth variation of the method of the invention, the translucent / transparent resin layer is applied to the filler particles adhering to the un-polymensed carrier layer.

According to an eleventh variation of the method of the invention, the un-polymerised carrier resin and the translucent / transparent resin are polymensed at the same time.

According to a twelfth variation of the method of the invention, the translucent I transparent filler particles are included in the photoluminescent carrier mixture and this mixture is applied to the substrate.

According to a thirteenth variation of the method of the invention, the translucent I transparent filler is inorganic or organic particles or a mixture(s) thereof.

According to a fourteenth variation of the method of the invention, the translucent / transparent filler is glass beads.

According to a fifteenth variation of the method of the invention, the resin coating on the translucent / transparent particles is either colourless or translucent or has a colour tinted translucence.

According to a sixteenth variation of the method of the invention, the luminous item is a handrail.

According to a seventeenth variation of the method of the invention, the luminous item is at.tachable to a wall or floor.

P1783 3 According to an eighteenth variation of the method of the invention, the luminous part of the luminous item is shaped to point in a particular direction.

According to a nineteenth vanation of the method of the invention, the luminous item is attachable to the tread or nose of a stair I step.

According to a twentieth variation of the method of the invention, the luminous item is a decorative feature.

In a preferred application of the method of the invention, a pultruded tube is gently abraded on its outer surface, degreased with a solvent cleaner and sprayed with a colourless resin-hardener camer mixture containing a photoluminescent substance to give an even annular coating. The viscosity of the resin mixture is controlled so that the resin is sprayable but will not drip off the underside of the tube. As soon as the spraying is complete and while the surface of the resin is still wet, colourless glass beads are sprinkled onto the wet surface so that they adhere to the wet resin mixture.

Straight tubes may be supported by pegs inserted into the bore and the tube rotated under the spray and particle sprinkler, in a single pass. When the full length has been sprayed and sprinkled, the tube is further rotated and tapped to cause any beads, which are not properly bonded, to fall off. Then a second resin layer is sprayed onto the surface of the glass beads, to give a uniform covering. This second resin layer is identical to the first, except that it contains no photoluminecent substance. Both resin layers are now polymensed simultaneously. This may include an initial period at room temperature, during which the tubes are rotated so that the coating does not flow under the force of gravity and form an oval, rather than annular coating. Final curing may be in an oven.

The second resin coats the surfaces of the beads and, via its surface tension, wets the whole of the free surface area of the beads down to, and bonds with, the first resin mixture.

Thus, the result is a single integral coating, tightly bonded to the tube.

1P1783 4 The coated tube described above may be used as the handrail to a flight of stairs. Under normal conditions the photoluminescent substance will absorb incident light and emit it as a visible, phosphorescent glow. In the dark, the emission of light will continue, causing the rail to glow and this will continue, with a gradually reducing light output, for a period, e.g. an hour, or more. The presence of this glowing handrail will greatly assist the evacuation of any building, subway, underground rail station, etc. By being totally independent of mains or battery power, the items of the invention will be 100% available, whenever required. The only proviso is that there must normally be sufficient ambient light incident upon the item to be absorbed so that the light output is at a level detectable by the human eye.

Additional items, made according to the method of the invention, include panels and direction indicators attachable to walls and panels attachable to the treads of stairs. In these cases the substrate of the invention would be the wall or the treads of the stairs. For blind people, the panels in the treads, etc, can be shaped and tapered to provide guidance.

The resin-covered glass beads give the handrails a warm, comfortable feel (as opposed to that of cold metal) and act as a wearing layer and provide protection against minor impacts and accidental damage. Fibreglass is excellent substrates for items produced according to the invention and, fibreglass tubes used as handrails, will be pleasant to touch.

For a clearer understanding of the invention and to show how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings in which:-Figure 1 is a sectional elevation of a substrate, showing the separate stages of the method of the invention; Figure 2 is a section of the substrate shown in Fig. 1 after application of the resin layer; Figure 3 is a section of the substrate and resin shown in Fig. 2 after the application of glass beads; Figure 4 is a section of the substrate, resin and beads shown in Fig. 3 after the application of the clear resin coating.

-Figure 5 is an elevation showing the application of the invention to a handrail and wall panels for a flight of stairs; and Figure 6 is a perspective view of a flight of stairs showing photoluminescent strips placed on the treads at I near the nose of each step.

1P1783 5 In the following description, the same reference numeral is used for the same part or for different parts fulfilling an identical function.

Fig. I shows the four separate stages of the method of the invention, moving from left to right, for the manufacture of a handrail 6. At the extreme left is a tubular member 2 with a centreline 1. Tube 2 may be any suitable item but a pultruded polymeric member is preferred. The outer surface 2A of tube 2 is roughened, e.g. with a suitable abrasive such as sandpaper, and degreased, with a solvent, to give a clean keyed, surface to which a polymerisable resin can adhere.

A colourless resin is mixed with an appropriate quantity of a photoluminescent substance.

After through mixing, the hardener is added, mixed in and the resultant mixture is sprayed, using a high volume, low pressure spray gun, on to tube 2A to give an even thickness, annular coating 3 (Fig. 2). Polyurethane resins are preferred and a resin / hardener ratio of 5:1 is suitable. Phosphor pigment, added at the rate of 10-20% by weight, is suitable for the handrail 6 of the application. Ideally, the sprayed coating is about 0.5 mm thick. The resin, phosphor pigment and hardener proportions quoted give a mixture 3, which is both sprayable but yet sufficiently viscous not to drip off tube 2.

While the resin mixture 3 is still wet, glass beads 4 are sprinkled uniformly onto the resin surface 3. Tube 2 is rotated during both the spraying and sprinkling processes so that uniform annular coatings 3 and 4 are applied around the whole surface 2A (Fig. 3). If necessary, a gentle pressure can be applied to ensure that beads 4 adhere positively to resin 3. By rotating tube 2 and tapping it, unattached glass beads 4 will fall off. At this point, a total, or partial cure, may be undertaken, as described below. This polymerisation will bind the glass beads 4 firmly onto the resin layer 3.

The final stage is to apply a spray of the same resin I hardener mixture as before (3), but without the pigment, to form a uniform coating 5 over beads 4 (Fig. 4). The surface tension and viscosity of the resin allows it both to form a uniform covering layer 5 over beads 4, fill the interstices between beads 4 and flow down to resin layer 3, i.e. to bind beads 4 into a high integrity annular layer around tube 2. Clear balotini glass beads, ideally passing a 0.5 mm mesh sieve, are preferred as they are basically spherical, uniform in size and will bind well with the resin mixture.

1P1783 6 At this point, either the final resin layer, or both resin layers are allowed to cure until polymensation is complete. As indicated above, the polymensation may take place either in two stages, i.e. after application of beads 4 and again after application of coating 5, or in a single stage, after the application of coating 5. In both cases, the cure, ideally, commences at room temperature, where the coated tubes 6 are supported on pegs, inserted in the bores, and rotated periodically so that the coating does not slump due to the effects of gravity. After about 30 minutes at room temperature, the tubes 6 are placed in an oven at 35 C for a further 120 minutes, until fully cured.

Resin spray 5 gives the final surface a smooth, clear coating, which is easy to grip and pleasant to touch. The application being taught is for the handrail 6 (Fig. 5), e.g. for a flight of stairs (Fig. 6) and it will be appreciated that, over a period of time, touching from many hands wiH wear away the surface, It is a feature of the invention that the glass beads and surface coating 5 provide a wearable layer through which the photoluminescent pigment can shine in the darkness. The wearable layer is resistant to minor impacts and accidental damage.

Fig. 5 shows how straight sections of handrail 6 are used with angled members 7 and end pieces 8 to form a continuous handrail for a flight of stairs. Angled members 7 would have members (not shown) affixable to appropriate members, e.g. the walls of the passageways, or central banisters, etc., by appropriate means (not shown). Intermediate supporting members (not shown) would be provided for use along long straight lengths 6, as required.

Below, in Fig. 6, a flight of stairs 14 is shown for reference purposes.

The stairs 14 (Fig. 6), consist of risers 11 and treads 12. At I near the nose of each step and affixed to the tread 12 is a photoluminescent strip 13 prepared according to the invention. To minimise wear of the photoluminescent member, raised protective edgings (not shown) are provided around the photoluminescent member 13, e.g. as described in co-pending UK Patent Application No. 06 05413.4. Additionally, though not shown in Fig. 6, photoluminescent strips may be incorporated into the actual nose of the stairs and I or into the upper part of the risers 11, so that they are more easily visible to persons approaching the bottom of the stairs or actually ascending 1P1783 7 Photoluminescent materials absorb incident light energy and emit that energy as visible light. When the ambient light is very low, the emitted photoluminescent light becomes visible to the naked eye. Thus, if the normal lighting fails, the handrail 6 and strips 13 will glow with visible light. This can be used to act as guidance to people approaching a flight of stairs 14 so that they will know where the steps begin and where to hold on to handrail 6.

An additional feature could be to apply the method of the invention to flat strips 9 and attach these to the walls of underpasses, underground train access passages, etc. These could be resin panels 9, either cast directly on to a substrate (not shown) for attachment to the wall, or cast in a mould, for removal and direct affixment to the wall. In this later case, the wall would be the substrate of the invention. An example of the use of such panels is shown 9 in Fig. 5 by placing them above handrails 6. This will act as additional guidance to people approaching and using the flights of stairs 14.

Though a clear resin is preferred for coating 5, appropriately tinted transparent coatings may be used for particular applications, e.g. greenish for level passages 9A and, say, pinkish for stairs 9B. Alternatively, photoluminescent pigments having different colours can be used for different items.

In normal access passages, panels 9 may be shaped into the form of arrows (not shown) to indicate the direction in which people should proceed towards the exit to leave the passageway. For blind people, shaped tactile tiling in the floor (not shown) could be provided. While these would appear as photoluminescent, visible directional indicators to the sighted, Blind people could sense them under their feet, or with sticks.

Polymeric substrates and balotini beads are preferred as they bond well with the polyurethane resin taught herein but any suitable materials and compatible resin systems may be used. The skilled man will know of the appropriate procedures for using polymensable resin systems.

The use of spherical glass beads 4 enables the illumination from the photoluminescent pigment in resin mixture 3 to be viewed from acute angles as the light will be reflected internally within the beads and refracted outwardly through resin coating 5. Thus, the photoluminescent items of the invention can be seen by people approaching, e.g. a staircase, rather than just by those actually on the stairs.

1P1783 8 The skilled man will appreciate many other applications of the principle of the invention, e.g. push panels on doors, arrows indicating the direction to the nearest escape route on the insides of the doors of hotel bedrooms, arrows affixed at regular intervals to walls and / or skirting boards (visible to escapees stooping under smoke clouds, obscunrig emergency lights), etc. Though the description to date has been written with reference to emergency escape routes, the method of the invention is equally applicable to decorative applications, e.g. features to decorate patios or the walls of houses adjacent to patios, garden paths and features in gardens, e.g. statues, gnomes, etc. Coloured tints in the surface coating 5 may be used to enhance the aesthetic charm of the decorative features. Such features would be visible after dark and could give an ethereal atmosphere to nocturnal garden parties.

In the above description, the pleasant nature of the handrail to the touch has been taught as a separate aspect to the main purpose of the invention, i.e. indication of escape routes.

Clearly, blind and partially sighted people will gain little or nothing from the photoluminesent aspects of the invention. However, such people usually have an enhanced sense of touch.

It is possible to vary the texture (tactile surface) of the handrail to indicate changing conditions, e.g. the approach of oncoming hazards, such as flights of stairs. For example, the end sections of the handrails, i.e. between points 15, past angled sections 7 to ends 8 (Fig. 5), could be provided with a rougher textured, tactile surface, e.g. by using clear angular-shaped particles 4, e.g. crushed glass, instead of clear, round Balotini beads.

In this case, a blind person approaching handrail 6 (and stairs 14) from the right, would feel end 8' of rail 6' and know that there were stairs 14 ahead because of the (relative) roughness of tactile surface 16'. Being forewarned, he I she would expect angled member 7', indicating descending stairs 14. When his / her hand passed 15', the tactile change to the normal pleasant surface 16 would indicate a flight of stairs 14 (i.e. as opposed to a single step). Descending further, he I she would encounter tactile change 15" and rougher surface 16" and be warned of the approach of the bottom of stairs 14. Though ends 8', 8" are shown, handrail 6 could be continuous along a corridor, down stairs and along another corridor. By applying the rougher, tactile surface 16' to only, say, the lower half of the rail 6' and 16" to only the upper half of rail 6", a blind person would know that the approaching stairs 14 were either respectively descending or ascending. Such advance indication would be a boon to blind people, especially in the stress of an emergency evacuation.

1P1783 9

Claims

Claims: 1 A method of making luminous items, comprising i) providing a

substrate; ii) affixing / applying a photoluminescent substance to the substrate to form a luminous item and iii) providing the luminous item for use; characterised in that the photoluminescent substance is present within a translucent I transparent carrier, which is fast / firmly bondable with the substrate and which protects the photoluminescent substance from regular wear and tear and accidental damage.

2 A method of making luminous items, as claimed in claim 1, wherein the substrate is an element attachable to a structural member.

3 A method of making luminous items, as claimed in claim 1, wherein the substrate is a structural member.

4 A method of making luminous items, as claimed in claims 2 or 3, wherein the camer is a polymensable resin.

A method of making luminous items, as claimed in claim 4, wherein the photoluminescent substance is intimately mixed with the carrier.

6 A method of making luminous items, as claimed in claim 5, wherein a layer of the carrier and photoluminescent substance is applied to the substrate.

7 A method of making luminous items, as claimed in claim 6, wherein particles of a translucent I transparent filler are applied to the un-polymensed carrier layer.

8 A method of making luminous items, as claimed in claim 7, wherein the un-polymensed carrier layer is polymensed so that the translucent / transparent filler particles applied thereto become permanently bonded therewith.

1P1753 10 9 A method of making luminous items, as claimed in claim 8, wherein a translucent / transparent resin layer is applied to the translucent I transparent filler particles bonded to the polymensed carrier layer.

10 A method of making luminous items, as claimed in claim 9, wherein the translucent I transparent resin layer is polymensed so that it forms a smooth external coating over the filler particles.

11 A method of making luminous items, as claimed in claim 7, wherein the translucent / transparent resin layer is applied to the filler particles adhering to the un-polymensed carrier layer.

12 A method of making luminous items, as claimed in claim 11, wherein the un-polymerised carrier resin and the translucent / transparent resin are polymensed at the same time.

13 A method of making luminous items, as claimed in claims 5 -12, wherein the translucent I transparent filler particles are included in the photoluminescent camer mixture and this mixture is applied to the substrate.

14 A method of making luminous items, as claimed in claims 7 -13, wherein the translucent / transparent filler is inorganic or organic particles or a mixture(s) thereof.

A method of making luminous items, as claimed in claim 14, wherein the translucent / transparent filler is glass beads.

16 A method of making luminous items, as claimed in claims 9 or 11, wherein the resin coating on the translucent / transparent particles is either colourless or translucent or has a colour tinted translucence.

17 A method of making luminous items, as claimed in any preceding claim, wherein the luminous item is a handrail.

18 A method of making luminous items, as claimed in any preceding claim, wherein the luminous item is attachable to a wall or floor.

1P1783 11 19 A method of making luminous items, as claimed in claim 18, wherein the luminous part of the luminous item is shaped to point in a particular direction.

A method of making luminous items, as claimed in any preceding claim, wherein the luminous item is attachable to the tread or nose of a stair I step.

21 A method of making luminous items, as claimed in any preceding claim, wherein the luminous item is a decorative feature.

22 A method of making luminous items, as described in and by the above statement with reference to the accompanying drawings.

1P1783 12