GB2268748A

GB2268748A - Improvements in or relating to anti-slip tread

Info

Publication number: GB2268748A
Application number: GB9213885A
Authority: GB
Inventors: William Leslie Whitelaw; Ronald Morton; Robert Ian Lawson
Original assignee: Gradus Ltd
Current assignee: Gradus Ltd
Priority date: 1992-06-30
Filing date: 1992-06-30
Publication date: 1994-01-19
Anticipated expiration: 2012-06-30
Also published as: GB2268748B; GB9213885D0

Abstract

A composition for an anti-slip tread comprises an epoxy resin, a blocked polyurethane and an inert aggregate. An anti-slip device is produced by arranging pieces of a first anti-slip material in a mould, pouring a second anti-slip material around spaces between the first anti-slip material and removing excess second material.

Description

IMPROVEMENTS IN OR RELATING TO ANTI-SLIP TREAD This invention relates to improvements in anti-slip treads and more specifically, but not exclusively, the invention relates to improvements in anti-slip devices which may be adhered to or formed integrally with floors, stair treads and the like. In particular reference is made to our co-pending application entitled Improvements in or relating to tiles and having the same filing date.

A problem with existing types of anti-slip treads has been that they could only generally be produced in one colour. This, for the most purposes has been sufficient, however, it has been necessary in certain applications to have alternating coloured zig-zag painted treads or chevrons with treads, so as to highlight an edge of a stair tread or walk-way. This was particularly important when the colour of the step, stair tread, walk-way or path, (which an anti-slip device borders), is the same colour as the anti-slip device per se. In certain environments, because of health and safety rules, it is obligatory to mark edges of stairways and steps with highlighted chevrons. A particularly efficient colour combination is yellow and black. This has usually been done with paint or dyes.

Excessive scuffing has in the past lead to the paint being rubbed away. This was clearly undesirable.

A problem with some anti-slip treads has been that they were not particularly hard wearing. Because the anti-slip treads were designed to provide a surface capable of creating friction with, for example, the sole of a shoe, particular attention was not paid to the durability of the tread. The results was that treads did not have a particularly long life.

Another known form of anti-slip tread consists of a hard mineral such as corundum in a resin matrix. While treads of this composition perform well they are hard and brittle and as a result are dificult to cut or drill as may be necessary for the purpose of installation.

The invention has been made with the above problems in mind.

According to a first aspect of the present invention there is provided a composition for an anti-slip tread comprising an epoxy resin, a blocked polyurethane and an inert aggregate.

Examples of an inert aggregate include minerals such as sand, silica, quartz, corundum, seashell, grit or any combination thereof; and similar hardwearing materials. The proportion of aggregate included depends inter alia upon the properties required and the particular aggregate selected.

The blocked polyurethane material is mixed with an epoxy resin. The relative proportions of blocked polyurethane to epoxy resin determine the flexibility and to some extent, the abrasion resistance of the product.

Because abrasion resistance is conferred on the product by the resin the invention makes it possible to achieve the desired abrasion resistance by employing a different and preferably cheaper aggregate than used in prior art products for the same abrasion resistance. For example where a prior art product uses corundum which is expensive in order to attain a desired abrasion resistance, the present invention may use quartz as an aggregate which is much cheaper than corundum and yet attain the same abrasion resistance.

The preferred blocked polyurethanes for use in the present invention are linear polymers. Although as previously stated the properties of blocked polyurethane and epoxy resin can be varied with ether and urethane groups containing a cross linked NCO group and urethane acrylate polyurethane modifiers. A particularly preferred composition contains 100 parts of blocked polyurethane to 18 parts of epoxy resin.

Curing and hardening of the composition may take place at or around room temperature. Accelerated curing may be achieved by raising the temperature. A curing agent such as an aliphatic amine or cycloaliphatic amine is preferably included in the composition.

Preferably 100 parts of epoxy resin are mixed with 60 parts cumene indene resin. The cumene indene resin provides an additive which reduces viscosity of the composition prior to curing. Mineral oil may be added in the range of from 100 parts resin to 20 parts mineral oil, 100 parts resin to 80 parts mineral oil. Preferably the mineral oil which is used is Coumerone Indene Resin.

Examples of suitable blocked polyurethanes are (i) linear polymers with ether and urethane groups, containing a cross linked, blocked NCO group and (ii) a urethane acrylate polyurethane modifier. These are a high wear resistance and when mixed with any of the aforementioned fillers produces an extremely hardwearing product.

It is known that polyurethanes react with moisture which may be present on the fillers. Blocked polyurethanes however do not react with water present on the fillers and consequently this is another advantage of using blocked polyurethanes in accordance with the invention.

Additives such as suitable dyes and/or defoaming agents may be added as and where required.

Preferably the blocked polyurethane and epoxy resin together with additives are mixed before the aggregate added and dispersed evenly throughout the mixture. The mixture is then poured into a mould or moulds and allowed to cure. Alternatively the mixture may be allowed to part cure and it may be extruded. Extrusion normally requires a lower viscosity mixture which in turn may affect the properties of the product.

According to a second aspect of the present invention there is provided a method of producing an anti-slip device comprising the steps of: arranging pieces of anti-slip material in a mould; pouring a second anti-slip material around spaces between the first anti-slip material and removing excess second anti-slip material.

Preferably the second anti-slip material is of a different colour to the first.

The first anti-slip material may be cut into squares or triangles and arranged in a pattern in a mould. The second material, when poured around the first begins to form bonds with the first material so as to form an homogeneous strip. Excess second material is removed. The strip thus formed is then allowed to cure.

One way of performing the invention will be described, by way of an example only, and with reference to the figure.

A blocked polyurethane material is mixed in the ratio of 18 parts with a suitable epoxy resin. A mineral oil such as Coumerone Indene Resin is added (resin 100 parts) in a ratio of 20 to 80 parts. A suitable aggregate such as sand, gravel or quartz is then added to the proportion as desired. A yellow dye is introduced and the mixture thoroughly mixed so that the dye is dispersed throughout the mixture.

The mixture is then extruded onto a conveyor belt 10. The resin mixture reacts with the hardener to cure strip 11 into a solid matrix. It will be appreciated that although reference to the strip 11 has been made the shape of the finished extrusion may be circular or star shaped a silhoutte or indeed any cross section which may be extruded.

The conveyor belt 10 passes through a heated portion 12 so as to accelerate hard curing of the resin matrix.

The strip 11 is then cut into portions of the desired thickness or width llA, 11B, 11C and l1D. These portions are placed in a suitable mould 13. A second mixture is then poured around these materials. The second mixture comprises a black dye stuff but is otherwise similar to the first. mentioned material.

Excess second material is scraped or otherwise removed.

The mould 13 is then heated with the result that bonding takes place between material of the existing shape and the new material. It will be noted that this bonding takes place without the provision of any additional bonding or adhesive material. The result is that a multicoloured anti-slip tread may be formed.

It will be appreciated that variation to the above mentioned method and embodiment may be made without departing from the scope of the invention. For example several different colour materials may be used to build up a word or image.

Claims

1. A composition for an anti-slip tread comprising an epoxy resin, a blocked polyurethane and an inert aggregate.

2. A composition as claimed in claim 1 wherein the inert aggregate includes minerals, sand, silica, quartz, corundum, seashell, grit or any combination thereof.

3. A composition as claimed in any preceding claim wherein the blocked polyurethanes are linear polymers.

4. A composition as claimed in any preceding claim wherein the blocked polyurethane is a linear polymer with ether and urethane groups, containing a cross-linked blocked NCO group.

5. A composition as claimed in any of claims 1 to 3 wherein the blocked polyurethane is a urethane acrylate polyurethane modifier.

6. A composition as claimed in any preceding claim wherein the composition contains substantially 100 parts of blocked polyurethane to 18 parts of epoxy resin.

7. A composition as claimed in any preceding claim wherein a curing agent is included in the composition.

8. A composition as claimed in claim 7 wherein the curing agent is aliphatic amine or cycloaliphatic amine.

9. A composition as claimed in any preceding claim wherein cumene indene resin is included in the compoXition .

10. A composition as claimed in any preceding claim wherein mineral oil is included in the composition.

11. A composition as claimed in any preceding claim wherein dyes and/or foaming agents are included.

12. A composition as claimed in any preceding claim wherein the block polyurethane and epoxy resin together with any additives are mixed before the aggregate is added.

13. A composition as claimed in claim 12 wherein the resultant mixture is poured into a mould and allowed to cure.

14. A composition as claimed in claim 12 wherein the resultant mixture is allowed to part cure and is then extruded.

15. A method of producing an anti-slip device comprising the steps of: arranging pieces of anti-slip material in a mould; pouring a second anti-slip material around spaces between the first anti-slip material and removing excess second anti-slip material, said first and second anti-slip materials having a composition according to claim 1.

16. A method as claimed in claim 15 wherein the second anti-slip material is of a different colour to the first anti-slip material.

17. A method as claimed in claim 16 wherein the first and second anti-slip materials otherwise comprise the same composition.

18. A method as claimed in claim 15 or claim 16 wherein the second anti-slip material forms bonds with the first material so as to form an homogeneous strip.

19. A method as claimed in claim 18 wherein said bonding is achieved by heating.

20. A composition or a method as hereinbefore described with reference to and as illustrated in the accompanying drawings.