GB2200931A

GB2200931A - Moulded products of silica, & resin binder

Info

Publication number: GB2200931A
Application number: GB08802576A
Authority: GB
Inventors: Daniel Dalton
Original assignee: DALTON MAUREEN ROSE
Current assignee: DALTON MAUREEN ROSE
Priority date: 1987-02-06
Filing date: 1988-02-05
Publication date: 1988-08-17
Also published as: GB8802576D0; GB8702741D0

Abstract

A moulded product comprising silica and a resin binder. The moulded product may be produced to foam a slate, a tile, cladding, coping, flooring, walling, fireplaces, paving, stairs, sills, lintels and arches.

Description

A MOULDED PRODUCT This invention relates to a moulded product.

There is always a need for products which can be moulded from new combinations of materials. The new moulded products are especially useful in the building industry. It is -an aim of the present invention to provide one such moulded product.

Accordingly, the present invention provides a moulded product comprising silica and a resin binder.

The moulded product may be produced to form a slate, a tile, cladding, coping, flooring, walling, fireplaces, paving, stairs, sills, lintels and arches. Obviously, if desired, the moulded product may be produced for other uses, for example billiard table tops.

Usually, the silica will be sand. The sand may be fine, medium or coarse sand.

The sand may be any desired type of sand so that the sand may be pit, 'dune, river, desert, foundry or glass sand.

The sand may be washed sand or non-washed sand.

Any suitable silica may be employed in the moulded product of the presentainvention. Thus, for example, the silica may be crystalline silica. The crystalline silica may be quartz, tridymite or cristobalite.

The use of fine sand or other silica materials is preferred since the moulded product then has a denser quality with a finer surface finish.

Preferably, the resin binder is an epoxy resin binder.

Any suitable type of resin binder may be employed.

Thus, or example, the resin binder may be a polyester resin binder or a soluble resin binder such as an acrylic resin binder or a PVA resin binder such for example as that sold under the trade name Unibond.

The resin binder may also be a hydrocarbon resin binder.

The resin binder, for example the epoxy resin binder, may be such that it is composed of two components with one component being a hardener component. The two components will be such that when they are mixed together, the resin binder sets hard. Any type of setting or curing system may be employed so that the resin binder may be arranged to set hard under the application of heat, or at ambient temperatures, or substantially instantaneously. The setting/curing time will normally depend upon the particular type of hardener component used in the resin binder. The hardener component should be such as to give good colour fastness.

It is preferred to produce the moulded product as cheaply as possible. Where the moulded product consists only of silica and a resin binder, relatively higher pressures may be required for some types of moulded product. It may be possible to produce the moulded product at relatively lower pressures when the moulded product includes a filler material.

The moulded product may or may not include a filler material. Where a filler material is used, high or low pressures may be employed to form the moulded product. The filler material may give the moulded product a finer denser water tight finish. Usually, the filler material will not be employed or will only be employed in small amounts, with high pressures.

Preferably, the filler material is crushed slate. Any type of slate may be employed.

Preferably, the crushed slate is in powder form. If the filler material is other than crushed slate, then the filler material is also preferably in powder form. The use of the powder stops the moulded product from being too coarse.

In combining the various materials to form the moulded product, it may be desirable not to employ too much filler material as the filler material tends to absorb the binder.

Sufficient of the filler material should preferably be employed to give a smooth fine finish. Any type of filler material may be employed including even powdered sand which is known as sand flour.

The moulded product may include a waterproofing agent, for example where the moulded product is to be produced in the form of a slate or a tile. With an epoxy resin binder, a waterproofing agent will usually not be required as the epoxy resin binder will usually give the moulded product sufficient water resistant properties.

The moulded product may include strengthening materials such for example as carbon fibre or glass fibre. The fibre may be in strand, matt or chopped form. Chopped strands in 3mm, 4.5mm and 6mm may be used.

The proportions of the materials employed in the moulded product may vary with the intended use of the moulded product. By way of example it is mentioned that the moulded product may be made from two-thirds silica material and onethird filler material, there being an appropriate amount of resin binder employed. The moulded product may be harder for increasing amounts of resin binder employed.

The moulded product may be produced from a dry mixture.

The dry mixture may be compressed or it may be vibrated and compressed. Vibration is generally preferred and it gives a good moulded product. High compression pressures are preferred. The pressures may be from 300psi to 50,000psi.

The moulded product may also be produced from a nearly dry mixture that is just damp. Such a nearly dry mixture will usually be compressed, or vibrated and compressed, in the same way as the dry mixture to produce the moulded product. The produced moulded product may be extremely hard.

If desired, the moulded product may be employed using a wet mixture. The wet mixture may be vibrated in a mould.

The wet mixture may be left to set in the mould without the application of external treatment such as heat and/or pressure.

The wet mixture can be pumped as a slurry into the mould or it can be introduced into the mould in any other desired way.

The use of the dry mixture is envisaged to be the cheapest way of producing the moulded product.

The silica or sand may be used in different natural colours as appropriate. Alternatively, desired colours in the moulded product may be employed by using colouring pigment material such for example as red iron oxide, green chromium oxide, carbon black, ferrite yellow, phthalocyanine blue and titanium dioxide.

The moulded product may be ground to a smooth surface finish if it is not otherwise produced to have a sufficiently smooth surface.

When the moulded product is in the form of slates and tiles, then the slates and the tiles may be interlocking or non-interlocking slates and tiles. Where the slates or tiles are interlocking slates or tiles, then any desired interlocking arrangement may be employed.

Reference will now be made to the following Example which is given for the purposes of illustration only and which describes the formation of a moulded product.

Example A A dry mixture was formed from two-thirds silicate sand, one-third crushed powdered slate and an appropriate amount of a resin binder in the form of an epoxy resin. The mixture was arranged to be very dry and it was vibrated in a mould. The mixture was compressed and allowed to set.

Compression pressures may be from 500 lbs. up to 500 tons (or from 30-400 atmospheres).

The produced moulded product was in the form of a slate or tile and the slate or tile was found to have good strength and water resistant characteristics.

It is to be appreciated that the Example given above is for the purposes of illustration only so that the ingredients can be varied. Thus, for example, a waterproofing agent can be added to increase the water resistance of the produced slate or tile. Also, a strengthening agent such as carbon fibre or glass fibre can be added. Any waterproofing agent and strengthening agent will be added to the mould before compressing the mixture. A moulded product other than a slate or tile may be produced such for example as a paving slab, a column or a beam. The crushed slate powder may be that known as fullersite. The crushed slate, which is used as a powdered filler, may be replaced by cristobalite silica which has been crushed to a fine powder and which is known as silica flour. If less sand is used than in the above Example and more fullersite or cristobalite, then an increase in the amount of resin binder employed is usually required.

The amount of resin binder employed can be reduced with reducing amounts of fullersite or the cristobalite.

The moulded product referred to in the above Example is produced from a dry mixture since such a way of producing the moulded product is very cost effective. However, the moulded product can be produced from a damp mixture or a wet mixture if desired.

The moulded product can be left to cure at room temperature or it can be force cured under heat. Microwave heat curing may also be employed.

The finished moulded product may be sealed, for example to give a smooth water-tight glazed surface. The finished moulded product may alternatively be sprayed with an epoxy resin surface coating. The surface coating can include any desired colouring materials. Other desirable surface finishes may be achieved by, for example, firing sand at tacky surfaces of the moulded product to give a granular finish.

Claims

1. A moulded product comprising silica and a resin binder.

2. A moulded product according to claim 1 and which is in the form of a slate, a tile, cladding, coping, flooring, walling, fireplaces, paving, stairs, sills, lintels and arches.

3. A moulded product according to claim 1 or claim 2 in which the silica is sand.

4. A moulded product according to claim 3 in which the sand is fine, medium or coarse sand.

5. A moulded product according to any one of the preceding claims in which the resin binder is an epoxy resin binder.

6. A moulded product according to any one of claims 1 to 4 in which the resin binder is a polyester resin binder.

7. A moulded product according to any one of claims 1 to 4 in which the resin binder is a soluble resin binder.

8. A moulded product according to claim 7 in which the soluble resin binder is an acrylic resin binder or a PVA resin binder.

9. A moulded product according to any one of claims 1 to 4 in which the resin binder is a hydrocarbon resin binder.

10. A moulded product according to any one of the preceding claims in which the resin binder is such that it is composed of two components with one component being a hardener component.

11. A moulded product according to any one of the preceding claims and including a filler material.

12. A moulded product according to claim 11 in which the filler material is crushed slate.

13. A moulded product according to claim 12 in which the crushed slate is in powder form.

14. A moulded product according to any one of the preceding claims and including a waterproofing agent.

15. A moulded product according to any one of the preceding claims and including a strengthening material.

16. A moulded product according to claim 15 in which the strengthening material is carbon fibre or glass fibre.

17. A moulded product according to any one of the preceding claims and which is produced'from a dry or a substantially dry mixture.

18. A moulded product according to any one of claims 1 to 16 and which is produced from a wet mixture.

19. A moulded product according to any one of the preceding claims and including colouring pigment material.

20. A moulded product according to any one of the preceding claims and which is in the form of a slate or a tile.

21. A moulded product according to claim 20 in which the slate or the tile is an interlocking slate or tile which is provided with an interlocking arrangement.

22. A moulded product according to claim 1 and substantially as herein described.