FR3004203A1 - SECURITY FLOOR COATING - Google Patents

Abstract

The invention is aimed primarily at a floor covering comprising: a base layer; disposed on said base layer a layer of laminated decoration comprising: a printed lower layer; o a transparent intermediate layer; and an upper layer comprising a hydrochromic product; and - disposed on said decorative layer a protective layer permeable to water. It also relates to a method of manufacturing such a coating.

Description

The present invention relates to a floor covering that can signal the presence of water and thus limit the risk of slips and falls. It also relates to a method for its manufacture. Plastic flooring, for example polyvinyl chloride (PVC), is a practical and economical solution for covering the floors of the home. Like most soils, these soils can become slippery when wet and thus pose a safety problem. This danger is recurrent in busy public spaces that require frequent cleaning, such as airports, hospitals or schools. At present, this problem is generally solved by excluding wet spaces from circulation during cleaning and then during drying. This method is, however, tedious and requires specific delimiting equipment, which slows down the cleaning operation and entails substantial costs. The object of the present invention is the development of a floor covering to alert the public of the risk of falling, without the need for human intervention. This object is achieved, according to the invention, by a floor covering whose appearance changes in contact with water through the incorporation of a hydrochrome product. Also, according to a first aspect, the invention provides a flooring comprising: - a base layer; disposed on said base layer a laminated decorative layer comprising: a printed lower layer; o transparent intermediate layer; and o an upper layer comprising a hydrochromic product; and disposed on said decorative layer a water-permeable protective layer. An essential aspect of the invention is the presence in the flooring of a hydrochromic material, the transparency of which varies in contact with water. Hydrochromic materials are known and a number are available on the market. Thus, the company Matsui markets a hydrochrome binder under the name "Hydrochromic White". SolarActive in Tarzana, USA, markets hydrochrome ink. Such a hydrochromic material may be in particular in the form of a biphasic mixture, one of the two phases of which changes its refractive index in the presence of water, and in which the index of the two phases is adjusted so that their refractive index coincides substantially, either in the presence of water or in its absence.

Indeed, when the refractive index of two phases differs, the light is reflected at the interfaces of these phases and is diffused, resulting in a low transparency of the material. In contrast, when the refractive index of the two phases is identical or very close, the light is poorly diffused and the transparency is high. The hydro-chromic materials thus pass from a light-diffusing state, presenting an opaque white appearance in the absence of pigments, to a transparent state, according to the humidity present. Thus, according to one embodiment, the hydrochromic product incorporated in the opaque flooring in the dry state but becomes transparent in the presence of water, revealing the underlying decor, not visible in the dry state. Such a coating shows in damp places a decor that can be designed to warn the public of the danger of slipping, for example. On drying, the refractive indices of the particles and the matrix deviate, and the hydrochrome product becomes opaque again by removing the decoration. The safety floor covering according to the invention therefore makes it possible to signal the presence of water reliably and automatically, without human intervention. Preferably, the base layer comprises a polyvinyl chloride (PVC) based formulation. According to one embodiment, the hydrochromic product comprises particles dispersed in a matrix. Preferably, the particles comprise silicic acid and wherein the matrix comprises a silicate gel. Advantageously, the upper layer of the layer of layered decoration also comprises one or more pigments. Preferably, the top layer of the laminate decorative layer further comprises polyurethane.

The protective layer that is permeable to water may in particular be discontinuous. It may include polyurethane. According to a second aspect, the invention relates to a method of manufacturing such a floor covering, comprising the steps of: (i) providing a base layer; (ii) applying, on the formed base layer, a laminate decorative layer, comprising the steps of: (a) forming a lower layer by printing; (b) applying, on the formed decorative layer, a transparent intermediate layer; and (c) applying to an intermediate layer formed an upper layer comprising a hydrochromic product; and (iii) applying a water-permeable protective layer to the layered decorative layer formed. Advantageously, the water-permeable protective layer is applied by means of a screen cylinder.

The invention will be better understood on reading the description which follows, given solely by way of example. According to one embodiment of the invention, the floor covering comprises three main layers: a base layer, a layer of decor and a protective layer. Other layers may be present, depending on the intended application. The flooring may be particularly resilient flooring. It can be supplemented by other layers, depending on the intended application. The basecoat is typically composed of a polyvinyl chloride (PVC) formation. Other polymers, however, may also be suitable. The decorative layer of the coating is laminated, since it consists of a printed lower layer, an intermediate layer and an upper layer. The base layer can in principle be any. It may in particular _include polyvinyl chloride (PVC). The lower layer can be printed especially directly on the base layer or on a suitable support. The printed patterns may in principle be any, but reasons for signaling a danger and / or caution, for example graphically, are particularly interesting. The intermediate layer of the laminated decorative layer is transparent. Its function is in particular to isolate the printed layer of water. The intermediate layer may in particular be formed of a varnish.

The upper layer of the layer of laminated decoration comprises the hydrochrome product. As described above, the transparency of hydrochromic products is modified in the presence of water. These products change from a light-diffusing and therefore opaque state to a transparent state or vice versa. As mentioned above, such a product may be in particular in the form of a biphasic mixture, for example of particles dispersed in a matrix, the refractive indices being different between the particles and the matrix. The difference in the refractive index between the dispersed phase and the matrix may be adjusted, for example, so as to be greater than 0.1, preferably greater than 0.2, and still more preferably greater than 0.3. Such a hydrochromic product may comprise particles comprising or substantially consisting of silicic acid and a matrix comprising or substantially consisting of a gel based on silicic acid.

In the absence of pigments, such a product will appear white in the dry state and transparent in the wet state or vice versa, depending on the chosen materials. When pigments are added to the hydrochromic product, the resulting mixture changes from a light shade, when there is light scattering, to a more colored hue, when there is little or no more diffusion of light.

According to one embodiment, the upper layer is entirely covered with hydrochromic product. In the absence of water, the hydrochrome product is opaque, and the underlying decoration is not visible, but the decoration will be revealed in the areas in contact with the water since the hydrochrome product is transparent there. According to another embodiment, a mixture of hydrochromic product and pigment is partially applied in the upper layer forming patterns. In the absence of water, the hydrochrome product is opaque, and the patterns are very little visible, but the patterns are revealed in the areas in contact with water since the hydrochromic product is transparent. In order to improve the adhesion and the mechanical properties, the upper layer may comprise, besides the hydrochromic product and the possible pigments, in addition a polyurethane resin. The coating finally has a protective layer to provide the required wear resistance. In order to maintain the sensitivity to water, the protective layer must be permeable to water. Several possibilities exist: the layer can be especially porous, or discontinuous. A suitable material for forming the protective layer is in particular polyurethane. The operation of the flooring according to the invention will be explained hereinafter for the case of a coating having a printed lower layer and an upper layer in which is distributed uniformly an opaque hydrocfirome compound in the dry state and transparent to the contact with water. When the coating is dry, the hydrochromic product in the upper layer diffuses the light and the resulting opacity completely obscures the decor of the underlying lower layer. When the coating is wet, the water passes through the protective layer and reaches the top layer, and the top layer becomes transparent, revealing the lower layer in wet areas. Once the water has dried, the top layer becomes opaque and the decor disappears again. The invention therefore makes it possible to have a floor covering having a selectively modified decoration in the humid zones. By providing appropriate decors, the public can be effectively warned against the risk of slipping and falling without the need for human intervention. A further advantage of the invention is the fact that the manufacture of the surface coating does not require any particular material and can be carried out analogously to the manufacture of a conventional surface coating. 20 25 30

Claims (10)

CLAIMS1.- Floor covering comprising: a base layer; disposed on said base layer a layer of laminated decor comprising: a printed lower layer; o a transparent intermediate layer; and o an upper layer comprising a hydrochromic product; and disposed on said decorative layer a protective layer permeable to water. The floor covering of claim 1, wherein the base layer comprises a polyvinyl chloride (PVC) based formulation. 3. Flooring according to claims 1 or 2, wherein the hydrochromic product comprises particles dispersed in a matrix. The floor covering of claim 3, wherein the particles comprise silicic acid and wherein the matrix comprises a silicate gel. 5. Flooring according to one of claims 1 to 4, wherein the upper layer of the decorative layer further comprises one or more pigments. 6. Flooring according to one of claims 3 to 5, wherein the upper layer of the decorative layer further comprises polyurethane. 7. Flooring according to claim 1 to 6, wherein the protective layer is discontinuous. 8. Flooring according to one of claims 1 to 7, wherein the protective layer comprises polyurethane. 9. A method of manufacturing a floor covering according to one of claims 1 to 8 comprising the steps of: (i) providing a base layer; (ii) applying, on the formed base layer, a laminate decorative layer, comprising the steps of: (a) forming a lower layer by printing; (b) applying, on the formed decorative layer, a transparent intermediate layer; and (c) applying to an intermediate layer formed an upper layer comprising a hydrochromic product; and (iii) applying a water-permeable protective layer to the layered decorative layer formed. The method of manufacturing a floor covering according to claim 9, wherein the water-permeable protective layer is applied by means of a screen roll.