DK150825B - BUILDING OR CONSTRUCTION ELEMENT WITH DECORATIVE EFFECT - Google Patents

Description

150825

The present invention relates to a building or structural element which appears as a natural stone with decorative effect.

Natural stones in the form of sawn or carved slabs, 5 fragments or building blocks are highly sought after because of their decorative effect. Slate or marble slabs or tiles in particular have been used for floor coverings and wall or wall coverings. Granite stones, which have been carved into irregular bricks or bricks for the shape of the brick, have also been used in the building industry, for example for building walls, for wall or facade cladding, for fencing or for garden tiles.

The use of natural stones in the construction industry is substantially limited by their often high cost and because these 15 materials are becoming scarce as the deposits in nature are exploited. Particularly in demand, marble and black granite are available in limited quantities and are sold at high prices.

Without extraction and chipping of natural stones, 20 pieces of waste appear in the form of small fragments and crumbs or powders that have no or little value. Attempts have been made to utilize such waste by comminuting and compressing, possibly after admixing a binder, to obtain building blocks or slabs. It is also known to apply a layer of coating containing particles of natural stone to a core of a cheaper material. However, the finished products usually did not have the same appearance as the original natural stones. Due to the comminution and the content of binder, the surface often has a uniform and dull appearance without structure and character.

SE Patent No. 224,515 discloses a coating composition, containing a mixture of ground natural stones such as marble waste, a pigment such as carbon black, and a binder. The ground filler comprises particles of two different grain sizes, the coarsest fraction 5 having a grain size of 0.5-1.0 mm. The pigment is semen usually carbon black in an amount of about 0.2% and a maximum of 0.5-1%. Such a product will have a uniform texture with gray or black color and without resemblance to a similar real natural stone.

10 Natural stone slabs are usually very brittle and can easily tear or break during processing, transport or use for the intended construction purpose.

It is an object of the present invention to provide a building or structural element that most closely resembles a natural stone, such as a marble slab, slate or granite stone, and which is at the same time substantially cheaper than a corresponding real natural stone in addition to having enhanced strength. especially tensile and bending strength, compared to a similar natural stone.

The invention thus relates to a building or structural element consisting of a core and a covering layer containing relatively coarse particles of natural stone or a synthetic mineral material of decorative effect, which particles are joined together by an organic binder, and the invention is characterized in that the coating contains graphite with a particle size of 0.02-1 mm and in an amount of 2-60% by weight, based on the total weight of graphite and the relatively coarse particles of natural stone or synthetic mineral material . According to the preferred embodiment of the invention, the cover layer contains 10-40% by weight graphite.

Both the relatively coarse particles of natural stone or synthetic mineral material and the particles of graphite have such a grain size that they are visible to the naked eye. This gives the surface an appearance like a natural stone 5 with a clear structure or contrast effect.

The content of graphite is of significant importance, because of its special crystal structure and grain size, it emphasizes the structure of the surface and gives a clear contrast effect with an attractive decorative appearance.

Such an effect cannot be achieved with, for example, carbon black.

The particles of natural stone in the cover may consist of slate, marble or granite. With these mineral materials, combined with the particles of graphite, products can be obtained which, until mistakenly, resemble massive sawn or carved 13 slate or stone of slate, marble or graphite, respectively.

Instead, particles of a possibly colored glass frit can be used, which can give special decorative effects.

Here, too, the content of graphite provides an improved contrast 20 and beautiful surface texture. The glass frit may consist of glass balls or broken glass.

By the term "relatively coarse particles" is meant particles of such size as to obtain a clear o-surface structure visible to the naked eye. In practice, the 25 lower limit of the grain size is approx. 0.02 mm, with an unarmed eye difficult or indistinguishable from individual grains of diameter below this value. However, the mixture can contain, without disadvantage, a small amount of fine powder with a grain size below 0.02 mm. The particles of the natural stone in the cover layer can have a size up to 5 mm.

However, the optimum effect is obtained at a particle size of 0.05 - 0.25 mm for both materials.

The amount of binder may be selected arbitrarily within the usual concentration ranges. If the amount of binder agent is particularly low, some relief effect can also be obtained, the amount of binder being too small to give a completely flat and smooth surface. This relief effect can be greatly emphasized if the coating of the cover layer is applied by sputtering. Although the content of organic binder is relatively low relative to the mineral particles, these will nevertheless be strongly anchored in the cover layer. The mineral particles are very close together and protect the organic binder from climatic influences, so that a long shelf life is obtained for a long time.

The addition of graphite also has the advantage that the coating material used to form the cover layer can achieve an appropriate consistency due to the lubricating properties of the graphite, although the solids content is high. This is important regardless of whether the cover layer is formed by spraying or flattening.

If the mineral particles consist of glass frit which is crushed down to the desired particle size, the usual glass frit used in the ceramic industry can be used.

Thus, these may be glass particles which are colored in a desired manner, such as in red, green, yellow, blue or other colors. White opal glass or black glass can also be used.

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Any mineral particulate material that provides a desired decorative effect can be used. It is not necessary to use the materials separately. Thus, particles of several different natural stones and / or synthetic mineral materials can be mixed. Thereby, attractive, over surfaces that are not similar to specific natural stones can be obtained, yet have a structure and character like a natural stone.

A special synthetic mineral material which can be used in conjunction with the present building and construction element is glass which, in a heat treatment, is made partially or completely crystalline and then crushed to the desired particle size. As an example of a material of this kind may be mentioned a product which is sold on the market under the trademark "Synopal".

The core used for the building or structural element may consist of any sufficiently inexpensive material. A suitable core material is a shaped body of burnt clay, such as a brick. This results in an extremely cheap product, especially if only one or two of the brick surfaces are provided with the covering layer in question.

The core may instead consist of a sheet of wood, asbestos cement, plaster, concrete or a foamed inorganic or organic material.

If wood is used for the core material, such as a waste wood board or a chipboard, a light material of good mechanical strength is obtained so that the product does not easily crack or break. Also asbestos cement, plaster or concrete 30 provide cheap products with good strength, especially if steel wire, fiberglass or net reinforcements or natural or synthetic fibers such as polyamide or polyester fibers are introduced.

Particularly lightweight products are obtained when the core consists of a foamed material and examples thereof are polyurethane foam or polystyrene foam. Also naturally occurring porous or foamy materials can be used as core material. An example of this is the mineral Vermicullite in expanded form.

The invention is illustrated by the following examples.

Example 1 10 100 g of marble powder (Pig Italy) with a grain size of approx. 200 mesh is mixed with 20 g of graphite powder, 200 mesh, and the mixture is stirred in 50 g of a liquid epoxy resin.

After the addition of amine hardener, the mixture is poured onto a raw wood plate and the coating is cured on standing for 24 hours at room temperature. The pulp is extremely lightweight from the outside and gives a gray coating which, after polishing, does not differ markedly from the normal appearance of marble.

Example 2 100 g of shale powder (blue black) with a particle size of about 20 200 mesh is mixed with 50 g of 200 mesh graphite powder. The mixture is stirred in 90 g of polyurethane, kneading the mixture well. Finish the mixture out on a wooden board and leave for 8-10 hours at 20-30 ° C.

After curing, the surface is grinded with a grain size 280 abrasive, then the surface is brushed with steel brush and polished with wax.

The surface obtained is indistinguishable from an ordinary slate plate.

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Example 3

Example 2 is repeated, but instead of pouring out the mixture, acetone is added to the mixture to obtain paint or spray viscosity, optionally with a float 5 (bentonite). The finished mixture is sprayed onto a wooden board and, after recommending 8-10 hours at 20-30 ° C, the treatment of Example 2 is done with grinding and brushing with the same final result.

Example 4 A mixture of 100 g of granite powder and 50 g of graphite powder, both with a particle size of 200 mesh, and 85 g of styrene-containing liquid polyester containing 2% benzoyl petroxide and a little accelerator are prepared. The mixture was kneaded carefully and poured onto a wooden board, after drying 15 in the oven or heat tunnel at approx. 80 ° C for 15 minutes, the surface should be stiffened with a steel brush, and the surface thus obtained can, - if the structure of the workpiece is otherwise granite-like, be confused with granite.

Example 5 To 70 g of marble powder or granite powder or shale powder, all having a particle size of 200 mesh, is added so much polyurethane that a consistency which could be termed a "dry" putty mass is obtained, then acetone is added to obtain the desired putty. -, paint, dup-25 pe or spray consistency.

After application to a wooden board and subsequent drying, the surface is sanded and / or brushed, and the result obtained is difficult to distinguish from ordinary marble, granite or slate.

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Example 6

A mixture of 100 g of crushed black granite having a particle size of 50 - 250 µm and 50 g of graphite having a particle size of 50 - 100 µm is stirred in 90 g of polyurethane and diluted with acetone to obtain spray viscosity.

With still stirring, the product is sprayed onto a plasterboard, an asbestos cement slab and a concrete slab respectively. In all cases slabs are obtained which closely resemble carved granite slabs.

Example 7

Example 6 is repeated with the change that the said coating material is sprayed onto a rigid polyurethane foam sheet having a weight of approx. 200 kg per The product resembles a carved granite slab, but is much lighter and still has a very high strength.

Example 8

A mixture of 100 g crushed white opal glass having a particle size of 20 - 250 µm and 3 g of graphite powder having a particle size of 50 - 100 µm is mixed with 30 g of 20 polyurethane and so much acetone that the mixture achieves smear consistency.

This coating material is applied to a side surface of a plain brick by means of a roller. After curing the cover for 8-10 hours at 20-30 ° C, a brick 25 is obtained, the coated surface of which is whitish or white-gray, but with a beautiful rough and contrasting structure.