WO2021170288A1

WO2021170288A1 - Floor element and a hollow floor system

Info

Publication number: WO2021170288A1
Application number: PCT/EP2021/000017
Authority: WO
Inventors: Markus Rießler; Lukas RATZEK
Original assignee: Knauf Gips Kg
Priority date: 2020-02-26
Filing date: 2021-02-19
Publication date: 2021-09-02
Also published as: EP4111013A1; JP2023516160A

Abstract

The invention relates to a floor element and a hollow floor system comprising at least one floor element.

Description

Floor element and a hollow floor system

Floor elements for hollow floor systems are well known and commonly used in the prior art. They are mounted on height-adjustable supports (support posts) and cover all building service installations, such as cables, wires and complete communication equipment, but also possible errors of the subfloor (structural floor), such as e. g. unevenness. In addition, these floor elements are so viable designed and adapted to accommodate all load levels according to technical requirements. Furthermore, they allow free access to the laid in the cavity floor cables, pipes and the built-in floor tanks with their connections, etc.

The floor elements (which may also be named as composite panels or base plates or raised access floor plates) differ in the state of the art according to the carrier material, top surface, bottom lining, dimensions and the thickness. The carrier material used is predominantly highly compressed wood-based materials, calcium sulphate materials (e. g. gypsum), calcium silicate materials or cement-bound materials. The top coverings can be textile, elastic coverings as well as tiles or parquet. The backs, on the other hand, i. e. the underlay, may be protected against moisture with aluminum foil or paints. The dimensions of the double floor elements are predominantly 600/600 mm, although special dimensions up to 1200/1200 mm are also possible. Depending on the material and the load requirement, the thicknesses of these floor elements may range from 19 to 50 mm, preferably, thicknesses of 30 to 38 mm find application. Important properties for floor elements are thus load requirements, requirements for fire safety (noncombustible), acoustic requirements, electrostatic requirements, dissipative requirements or reverse antistatic requirements. Further, since as mentioned above the floor elements usually are mounted on height- adjustable supports (support posts), which are usually made of metal, the dissipation follows through the floor element (or at least in the state of the art at its side). For example, base plates for hollow floors in DE 20 2007 017 237 U1 may have an edge band of an electric conductive plastic material applied with a hot melt adhesive at least on one end face of the base plate. Via this edge band, the base plate has electrical conductivity between top and bottom, which gives good dissipation of an electrostatic charge from the top to the bottom of the base plate and to the metal support posts. However, it is an extra step and thus costly to provide these edge bands on every base plate.

In DE 102 00 292 A1 a conductive property for a flooring panel is realized inter alia with a panel, which is made from polyurethane and metal pieces or metal flakes. Further, it is possible to improve the flooring panel with colored chips. However, the panel might reach only a rather low level in fire-resistance classification of construction products and building elements DIN EN 13501-1 :2010-01 due to the polyurethane body.

A different approach is used in US 2013/0047529 A1 , where the core panel is encapsulated by two metal pans and a dissipative coating. Here, the core panel may be a fiberboard, a cement board, a concrete board and others. However, encapsulation with steel is costly and complicated.

As mentioned above all these solutions have disadvantages. Based on this prior art, the invention is based on the object to provide an easy and cheap producible solution of floor elements preferably for hollow floor systems. These floor elements should be at least dissipative and thus be useful e.g. in hospitals, for example in operation rooms, in radiology, in laboratories and supply rooms. In addition, the inventive floor elements can be used in the industrial sector for example in computer rooms, in data rooms, in clean rooms and in electronic departments. Further, these panels should be stable, noncombustible and visually appealing. This object is achieved by a floor element comprising the features in claim 1 a hollow floor system comprising the features of claim 12 and a method for producing a floor element comprising the features of claim 14.

Surprisingly, the floor element according to claim 1 is not only stable and noncombustible due to its cementitious core but also has dissipative properties, preferably with a resistance between 10⁶ and 10⁹ Ohm (W). Thus, the inventive floor element can be used e.g. in computer rooms or hospitals as mentioned above, where a combination of stability, noncombustibility and dissipation is necessary. In addition, it is believed without being bound to theory that the inventive floor element does not lose the dissipative property over time.

The cementitious core in the present application can comprise any material, substance, or composition that can set chemically, such as for example cement or stucco, along with any suitable additives. Non-limiting examples of materials that can be used in the cementitious core include Portland cement, sorrel cement, slag cement, fly ash cement, calcium alumina cement, water-soluble calcium sulfate anhydrite, calcium sulfate a-hemihydrate, calcium sulfate b-hemihydrate (“stucco”), natural, synthetic or chemically modified calcium sulfate hemihydrates, calcium sulfate dihydrate ("gypsum," "set gypsum," or "hydrated gypsum"), and mixtures thereof. As used herein, the term "calcium sulfate material" refers to any of the forms of calcium sulfate referenced above. Preferably, the cementitious core comprises cement, concrete, calcium sulfate material, or mixtures thereof, preferably calcium sulfate material. E. g. calcium sulfate dihydrate comprises a lot of crystal water so that the fire-resistance of the floor element can be improved. Preferably, the inventive floor element preferably reaches the classification “A2fi-s1” according to EN 13501- 1 :2010-01.

Further, the cementitious core may comprise stabilizing additives. E. g. the cementitious core may comprise glass fibers and/or paper fibers, preferably paper fibers. However, other fibers are possible, too. The fibers (e.g. paper fibers) can help to improve the stability of the floor element. The amount of fibers in the cementitious core of the floor element preferably may not exceed 15 wt.-% of the total weight of the cementitious core, may not exceed preferably 10 wt.-% of the total weight of the cementitious core. Further, the thickness of the inventive floor elements may range from 19 to 50 mm, preferably, thicknesses of 30 to 38 mm. Most preferably, the cementitious core may comprise calcium sulfate material and paper fibers. With that combination, fire-resistance and stability can be improved at the same time.

The at least partially synthetic top surface layer may be a substantially transparent layer and/or a hardened, preferably with UV light hardened, layer. However, a non- transparent layer is possible, too. A substantially transparent top surface layer is helpful, because that makes the layer below the at least partially synthetic top surface layer visible, which may be suitably designed for the purpose of the floor. Even more preferred is a transparent at least partially synthetic top surface layer. A hardened, preferably with UV light hardened, layer is advantageous, because the hardness of the layer can be produced easily, e.g. just by shining UV light onto it. Further, hardening with UV light is a fast method of hardening.

The at least partially synthetic top surface layer may comprise metal and/or metal oxide, preferably metal oxide and may further comprise an acrylated resin. The acrylated resin may be a diacrylate. In a preferred embodiment, the at least partially synthetic top surface layer may comprise two sublayers. The first sublayer may be identical with the at least partially synthetic top surface layer described above. The second sublayer, which may be positioned below the first sublayer may comprise metal and/or metal oxide, preferably metal oxide and may further comprise an acrylated resin as mentioned above and may additionally comprise an additive for abrasion resistance, e. g. aluminum oxide. Preferably, both sublayers may be hardenable with UV light. Further, even with two sublayers the classification “A2fi-s1” according to EN 13501- 1 :2010-01 may still be ensured. Further, as mentioned above in DE 102 00 292 A1 flooring panels can be provided with colored chips to modify and improve the design of the floor elements. However, motives are very limited by providing colored chips. Thus, the invention is also based on the object to provide an easy and cheap producible solution of panels, preferably for hollow floor systems, with an improved design. However, the other properties like noncombustibility and dissipation should still be present.

This object is achieved by a floor element comprising the features of claim 1 wherein between the cementitious core and the at least partially synthetic top surface layer a layer of ink is arranged. Surprisingly, thereby it was possible to keep these above- mentioned advantages a floor element. Preferably, the layer of ink may be a printed layer of ink, more preferably a digitally printed layer of ink. However, the layer of ink preferably may not comprise the metal and/or metal oxide as present in the at least partially synthetic top surface layer.

The layer of ink, which can be designed in many ways, especially when (digitally) printed in uncountable ways can give the floor element a visually appealing surface and the design of the floor element can be improved a lot. No need to cover these elements with carpet or other materials is necessary, which saves time and money. It is a further advantage of the inventive floor element (with or without a layer of ink) that no kind of top covering like parquet, carpet or others is necessary, since this is costly and takes more time to install. Instead, with the partially synthetic top surface layer the floor element is finished.

In a further preferred embodiment, between the cementitious core and the layer of ink a priming layer may be arranged. This priming layer may be a white paint, and might help to have evenly bright surface to which the layer of ink can be applied. Preferably, the priming layer may comprise an acrylate oligomer. Preferably, the priming layer may comprises metal and/or metal oxide, preferably metal oxide. The metal and/or metal oxide in the priming layer may help to keep the dissipation property through the floor element.

In a further preferred embodiment, the metal and/or metal oxide may be in the form of powder or swarf, preferably powder. The metal and/or metal oxide can in accordance with the present invention also be present applied on one or more substrate materials. Suitable substrate materials comprise for example mica, barium sulfate, titanium oxide, silicon oxide, aluminum oxide and combinations thereof.

In a further preferred embodiment, the metal and/or metal oxide may be selected from the group consisting of aluminum, iron, silver, copper, indium, rhenium, antimony, tin, titanium, any of the metals of the rare earths, rhenium(IV)-oxid, aluminum oxide, antimony oxide, antimony(lll)-oxide, indium oxide, tin oxide, tin(IV)- oxide, titanium oxide, titanium(ll)-oxide, titanium(lll)-oxide and titanium(IV)-oxide, oxides of the rare earths or any mixture thereof, preferably antimony, tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, oxides of any of the metals of the rare earths and mixtures thereof. If no oxidation state for the metal in the oxide is given, all possible oxidation states are meant. Metal and/or metal oxide in powder can be mixed easily with other components, like the at least partially synthetic top surface layer, as well as the sublayers mentioned above and/or the priming layer. Thereby, the dissipative property through the floor element can be kept.

In a further preferred embodiment, the amount of metal and/or metal oxide in the at least partially synthetic top surface layer and/or the priming layer may be between 2 and 10 wt.-%, preferably between 3 and 8 wt.-%, most preferably between 4 and 6 wt.-%. All amounts are according to the total weight of the respective layer. The amount of metal and/or metal oxide thereby may be kept as small as possible, but as big as necessary to keep the dissipative property through the floor element. Further, the above mentioned amounts of metal and/or metal oxide may count as well for the above mentioned sublayers or other layers, which may part of the floor element. Some of them will be discussed later.

However, it should be emphasized that not all layers in one floor element that comprise metal and/or metal oxide necessarily need to comprise the same amount of metal and/or metal oxide. Further, it should be mentioned that generally higher amounts of metal and/or metal oxide are possible, but may be uneconomic.

In a further preferred embodiment, the floor element may have a resistance between 10⁶ and 10⁹ Ohm and/or may be noncombustible according to EN 13501-1 :2010-01. A resistance of between 10⁶ and 10⁹ Ohm qualifies for dissipative property according to EN 1081:2017-04.

In a further preferred embodiment the cementitious core may have a thickness of between 19 and 50 mm, preferably between 30 and 38 mm, and/or the at least partially synthetic top surface layer may have a thickness of between 30 and 150 pm, preferably between 40 and 120 pm, and/or the layer of ink may have a thickness of between 15 and 50 pm, preferably between 20 and 40 pm.

Further, other layers can be applied. For example, between the cementitious core and the priming layer a layer of putty can be applied. Further, if a layer of putty is applied, between the cementitious core and the layer of putty a layer of adhesion promoter can be applied. However, all these layers preferably may include a small amount of metal and/or metal oxide.

It has to be noted that it is also possible to apply other layers, e.g. a protective layer at the bottom surface of the cementitious core. A protective layer may protect the floor element against moisture with e. g. layer of aluminum foil. Another embodiment of the present invention is a hollow floor system for providing access beneath a floor comprising a structural floor, at least one floor element according to the invention, at least one support post extending substantially upward from a structural floor.

A support post for hollow floor system is known for the skilled person. Preferably, a pedestal may be placed on each support post for resting the access floor elements thereupon. Preferably, the at least one support post may be at least dissipative, preferably conductive. Most preferred is a support post made of (conductive) metal.

Another embodiment of the present invention is a method for producing a floor element, characterized in that

- a cementitious core is provided, - a priming layer is applied on the top surface of the cementitious core,

- a layer of ink is printed, preferably digitally printed, on the priming layer,

- an at least partially synthetic top surface layer is applied on the layer of ink.

This method allows producing easily a floor element with the above-mentioned advantages over the state of the art. The top surface of the cementitious core is the surface, which would be visible, when the floor element is mounted, without any layers on its top surface, or in other words, which will be pointing up in the mounted state. Preferably, the at least partially synthetic top surface layer may comprise a first and a second sublayer.

Preferably, the method may be characterized in that between the top surface of the cementitious core and the priming layer

- a layer of adhesion promoter, and/or

- a layer of putty is applied.

The adhesion promoter may comprise an acrylate. The putty may comprise an acrylate oligomer. Both layers preferably comprise metal and/or metal oxide as defined e.g. for the at least partially synthetic top surface layer. Both layers may preferably be hardenable with UV light. However, even more layers are possible. Preferably, all of them may comprise metal and/or metal oxide as defined e.g. for the at least partially synthetic top surface layer.

Another embodiment of the present invention is the use of at least one floor element according to the present invention for a hollow floor system according to the present invention.

Additional advantages and novel features of the invention will be set forth in the example which follows, and in part will become apparent to those skilled the art or upon examination of the description above or may be learned by practice of the invention. The example shows the preferred embodiment of the invention by way of illustration of the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the scope and spirit of the present invention. Accordingly, the descriptions are to be regarded as illustrative, and not as restrictive. Example

A floor element according to the invention has been produced according to the method mentioned above.

As cementitious core the “GIFAfloor DB 36 green” was used. The “GIFAfloor DB 36 green” comprises gypsum and fibers. The fibers are in an amount of less than 15 wt.-%.

The cementitious core used in this example is slightly beveled at the top surface. However, none of the layers that are applied on the top surface of the cementitious core arrives on any of the side surfaces of the cementitious core. The side surfaces of the cementitious core are the surfaces, which are between the top surface and the bottom surface of the cementitious core and which are substantially orthogonal to the top surface and the bottom surface of the cementitious core. First a layer of adhesion promoter was applied, followed by hardening this layer with UV light. Then a layer of putty was applied, followed by hardening this layer with UV light. Then the priming layer was applied, followed by hardening this layer with UV light. Then the ink layer was printed digitally. Then the second sublayer of the at least partially synthetic top surface layer was applied, followed by hardening this layer with UV light. Then the first sublayer of the at least partially synthetic top surface layer was applied, followed by hardening this layer with UV light. All layers apart from the ink layer and the cementitious core in this example comprise about 5 wt.-% of metal and/or metal oxide. The floor element was tested according to fire resistance (EN 13501-1:2010-01) and got the classification A2n-s1. Further, the dissipative properties were tested according to EN1081. The result was in between 10⁶ and 10⁹ Ohm. Further, the floor element has been tested on formaldehyde according to EN 16516:2018-01 resulting in “indoor air comfort gold”-classification of eurofins.

Claims

1. Floor element, comprising a cementitious core and an at least partially synthetic top surface layer, characterized in that the at least partially synthetic top surface layer comprises metal and/or metal oxide, preferably metal oxide.

2 Floor element according to claim 1 , characterized in that the cementitious core comprises cement, concrete, calcium sulfate material, or mixtures thereof, preferably calcium sulfate material.

3 Floor element according to any of claims 1 or 2, characterized in that the cementitious core comprises glass fibers and/or paper fibers, preferably paper fibers.

4 Floor element according to any of claims 1 or 3, characterized in that the at least partially synthetic top surface layer is a substantially transparent layer and/or a hardened, preferably with UV light hardened, layer.

5 Floor element according to any of claims 1 to 4, characterized in that between the cementitious core and the at least partially synthetic top surface layer a layer of ink, preferably a printed layer of ink, more preferably a digitally printed layer of ink, is arranged.

6 Floor element according to any of claims 1 to 5, characterized in that between the cementitious core and the layer of ink a priming layer is arranged.

7. Floor element according to any of claims 1 to 6, characterized in that the priming layer comprises metal and/or metal oxide preferably metal oxide.

8. Floor element according to any of claims 1 to 7, characterized in that the metal and/or metal oxide is selected from the group consisting of aluminum, iron, silver, copper, indium, rhenium, antimony, tin, titanium, any of the metals of the rare earths, rhenium(IV)-oxid, aluminum oxide, antimony oxide, antimony(lll)-oxide, indium oxide, tin oxide, tin(IV)-oxide, titanium oxide, titanium(ll)-oxide, titanium(lll)-oxide and titanium(IV)-oxide, oxides of the rare earths or any mixture thereof, preferably antimony, tin oxide, indium oxide, antimony oxide, aluminum oxide, titanium oxide, oxides of any of the metals of the rare earths and mixtures thereof.

9. Floor element according to any of claims 1 to 8, characterized in that the amount of metal and/or metal oxide in the at least partially synthetic top surface layer and/or the priming layer is between 2 and 10 wt.-%, preferably between 3 and 8 wt.-%, most preferably between 4 and 6 wt.-%.

10. Floor element according to any of claims 1 to 9, characterized in that the composite panel has a resistance between 10⁶ and 10⁹ Ohm and/or is not flammable according to EN 13501-1:2010-01.

11. Floor element according to any of claims 1 to 10, characterized in that the cementitious core has a thickness of between 19 and 50 mm, preferably between 30 and 38 mm, and/or the at least partially synthetic top surface layer has a thickness of between 30 and 150 pm, preferably between 40 and 70 pm, and/or the layer of ink has a thickness of between 15 and 50 pm, preferably between 20 and 40 pm.

12. Hollow floor system for providing access beneath a floor comprising a structural floor, at least one floor element according to claims 1 to 11 and at least one support post extending substantially upward from a structural floor.

13. Hollow floor system according to claim 12, characterized in that the support posts are at least dissipative, preferably conductive.

14. A method for producing a floor element, preferably according to any of claims 1 to 11 , characterized in that

- a cementitious core is provided,

- a priming layer is applied on the top surface of the cementitious core, - a layer of ink is printed, preferably digitally printed, on the priming layer,

- an at least partially synthetic top surface layer is applied on the layer of ink

15. The method according to claim 14, characterized in that between the top surface of the cementitious core and the priming layer

- a layer of adhesion promoter, and/or - a layer of putty is applied.