DECORATIVE SURFACE COVERING WITH ANTIPATHOGENIC PROPERTIES

Background of the Invention

[0001 ] The invention generally relates to decorative surface coverings, in particular flooring and wallcovering, used as surface finish, e.g., in buildings. The invention more specifically relates to decorative surface covering having antipathogenic properties.

[0002] Polymer-based surface coverings, also called polymeric or synthetic surface coverings are well known. Generally, they are made of rubber, polyolefins, polyesters, polyamides, polyurethanes or PVC (polyvinyl chloride). They present specific properties, particularly in terms of mechanical resistance, wear and indentation resistance, but also in terms of comfort, softness, sound and heat insulation, resistance to fire, etc.

[0003] Among polymer-based surface coverings, so-called homogeneous surface coverings and multilayer surface coverings are also well known. Another type of surface covering includes carpet (e.g., in accordance with European standard EN 1307:2014+A3:2018). Heterogeneous flooring comprises of a wear layer and other layers which differ in composition and/or design and can contain a reinforcement (see, e.g., ISO standard 10582:2017). In contrast, a homogeneous floor covering is defined as a floor covering with one or more layers of the same composition and colour, patterned throughout its thickness (see, e.g., ISO standard 10581 :2019). Heterogeneous, homogeneous and carpet flooring may be provided in tile, plank or roll form.

[0004] A need has arisen for providing surface coverings with enhanced antipathogenic properties, while preserving the other properties. Furthermore, the incorporation of antipathogenic properties should be compatible with existing fabrication processes.

[0005] The increased interest in antipathogenic properties of surface coverings may be due to the COVID-19 pandemic, during which people developed awareness toward best practices for avoid the spread of SARS-CoV-2 as well as of other viruses and microorganisms. It can be observed that research on surfaces that impede adherence and/or spread of pathogens has gained attractiveness in industry. Summary of the Invention

[0006] As used herein, the term "antipathogenic" refers to a substance, compound or material that inhibits or stops growth of, or kills, infectious agents (pathogens such as, e.g., microbes, viruses, fungi, etc.) on non-living surfaces, e.g., a substance, compound or material having antimicrobial, antifungal, fungistatic, antiviral, viricidal, bactericidal and/or bacteriostatic properties. The term “pathogen” refers to an infectious microorganism or agent, in particular to a virus, microbe, bacterium, protozoan, prion, or fungus. As used herein, the term “microbe” designates a microorganism, especially a bacterium (causing disease or fermentation), an archaeon, an eukaryote, a protists, or a fungus, existing in a single-celled form or as a colony of cells.

[0007] A first aspect of the invention relates to a decorative surface covering for finishing work in a building, such as, e.g., flooring or wallcovering, comprising one or more support layers, a use-surface layer supported by the one or more support layers. The use-surface layer and/or at least one of the one or more support layers comprises an antipathogenic thermoplastic or crosslinked polymer material. For simplicity, a layer containing antipathogenic thermoplastic or crosslinked polymer material may be referred to hereinafter as an “antipathogenic layer”.

[0008] The expression “use-surface layer” designates the layer of the decorative surface covering that is exposed or apparent to the user, after installation of the decorative surface covering. In case of flooring, the “use-surface layer” may be referred to as the wear layer in the case of so-called resilient flooring (“vinyl” or like flooring) or as pile in the case of a carpet. The decorative surface covering according to the invention may comprise, e.g., heterogeneous flooring (preferably according to ISO standard 10582:2017), a homogeneous floor (preferably according to ISO standard 10581 :2019) or a carpet (preferably according to European standard EN 1307:2014+A3:2018). The decorative surface covering according to the invention may be provided in tile, plank or roll form.

[0009] The qualifier “decorative”, as used herein, is intended to imply that the item thereby qualified, such as the surface covering, remains visible in normal use (as an item of finishing work). The use of the term, should not, however, be taken to imply any particular aesthetic appearance. The expression “decor layer” designates a layer with a decorative motif. Examples of decor layers include print layers, in particular, rotogravure-printed layers and digitally printed layers.

[0010] The term “thermoplastic” (polymer) material encompasses plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling. Thermoplastic (polymer) material may comprise thermoplastic polymers and, optionally, one or more plasticizers, (mineral or organic) fillers, and further additives (e.g., impact modifiers) or processing aids. Thermoplastic polymers include, for example: polyacrylic acid, polyacrylate, polyamide, polyester, polylactic acid (PLA), polycarbonate, polyether sulfone (PES), polyether ether ketone (PEEK), polyetherimide (PEI), polyethylene, polypropylene (PP), polystyrene, polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), acrylonitrile butadiene styrene (ABS), etc.

[0011 ] In contrast, the expression “crosslinked” (polymer) material designates polymer material that has been irreversibly hardened through crosslinking between polymer chains so as to generate an infusible and insoluble network of polymer. Crosslinked (polymer) material may include, e.g., one or more thermoset or radiation- cured polymers. Radiation-cured polymers include, in particular, UV-cured and/or electron-beam-cured polymers. Crosslinked (polymer) material may comprise thermoset and/or radiation-cured polymers (e.g. polyurethane, polyimide, epoxy, etc.) and, optionally, one or more plasticizers, (mineral or organic) fillers, and further additives (e.g., impact modifiers, photoinitiators, antioxidants, etc.) or processing aids.

[0012] The antipathogenic polymer material may comprise an antipathogenic agent anchored (e.g., covalently bonded) to the macromolecular polymer chains and/or to any filler particles (e.g., calcium carbonate, chalk, limestone, gypsum, talk, dolomite, etc.) The anchoring of the antipathogenic agent within the thermoplastic or crosslinked polymer material may prevent migration, lixiviation and washing-off of the antipathogenic agent. The anchoring may thus contribute to mitigating release of antipathogenic agent into the environment and to maintenance of antipathogenic action over prolonged time, e.g., over the lifetime of the decorative surface covering (several years, e.g., 2, 5, 7, 10, 12, 15 or 20 years). These effects may be of particular interests in flooring or wallcovering intended for medical or care-giving institutions (e.g., hospitals, retirement homes, etc.)

[0013] It may be the use-surface layer that comprises the antipathogenic thermoplastic or crosslinked polymer material. Additionally, or alternatively, at least one of the one or more support layers could comprise antipathogenic thermoplastic or crosslinked polymer material. According to embodiments, the decorative surface covering could comprise a backing layer including the antipathogenic thermoplastic or crosslinked polymer material. If the decorative surface covering includes several layers containing antipathogenic thermoplastic or crosslinked polymer material, the antipathogenic agent may be the same for the different layers, or different. Each antipathogenic layer may target the same or different types of pathogens. A usesurface antipathogenic layer may preferably target viruses and/or bacteria, while an antipathogenic layer located on the back of the decorative surface covering (backing layer) may preferably target bacteria and/or fungi.

[0014] The antipathogenic thermoplastic or crosslinked polymer material may provide the layer that comprises the antipathogenic thermoplastic or crosslinked polymer material with a hostile surface. Such hostile surface preferably prevents or mitigates attachment of pathogens (in particular, viruses, bacteria and/or fungi) thereon by a physical mode of action, e.g., surface charge modification, potential barrier generation. The hostile surface may be configured, through the antipathogenic agent, to prevent or mitigate biofilm formation thereon. This may be effected by surface charge modification caused by the antipathogenic agent. Additionally, or alternatively, the antipathogenic agent may be selected so as to interfere with quorum-sensing (QS) signalling systems of the target pathogen(s). The antipathogenic agent could, e.g., include a QS inhibitor.

[0015] The thermoplastic or crosslinked polymer material may comprise, as the antipathogenic agent, a compound selected from the group consisting of: a Ca compound, a Na compound, a K compound, a Mg compound, a Ag compound, a Cu compound, a Zn compound and a Ti compound. As an antipathogenic agent, a Zn compound could be selected, e.g., from the group consisting of: zinc oxide, zinc acetate, zinc carboxylate, zinc acetylacetonate, zinc pyrithione, zinc salt of pyrrolidone carboxylic acid (ZnPCA), zinc pyrrolidone, zinc hydroxide, and mixtures thereof. The thermoplastic or crosslinked polymer material could comprise, e.g., from 0.01 to 0.15 wt%, preferably from 0.03 to 0.075 wt%, of zinc.

[0016] As indicated above, the decorative surface covering may comprise a carpet (e.g., in the form of tiles or rolls). The use-surface layer in this case preferably includes a layer of pile and the one or more support layers preferably include one or more backing layers.

[0017] The layer of pile could include synthetic fibers comprising or consisting of the antipathogenic thermoplastic or crosslinked polymer material. All or only part of the fibers of the layer of pile may comprise or consist of the antipathogenic thermoplastic or crosslinked polymer material. Indeed, in order to reach an overall satisfying antipathogenic activity of the carpet, it might not be necessary to use the antipathogenic thermoplastic or crosslinked polymer material for all pile fibers. The synthetic fibers comprising or consisting of the antipathogenic thermoplastic or crosslinked polymer material preferably represent at least 5% by weight of the fibers of the layer of pile. The synthetic fibers comprising or consisting of the antipathogenic thermoplastic or crosslinked polymer material may, preferably, be (statistically) uniformly (randomly) or regularly distributed over the carpet surface.

[0018] The synthetic fibers consisting of the antipathogenic thermoplastic or crosslinked polymer material may provide at least 5% (more preferably at least 10% or even at least 20%) of the specific surface area of the layer of pile, i.e., the total surface area of the layer of pile per unit of mass, determined in accordance with standard ISO 9277:2010.

[0019] The layer of pile preferably comprises fibers made from PA (polyamide, such as, e.g., PA66 or PA6), PE (polyethylene), PET (polyethylene terephthalate) or PP (polypropylene). The fibers with the antipathogenic thermoplastic or crosslinked polymer material may also comprise these polymers as the polymers, into which the antipathogenic agent is incorporated.

[0020] The decorative surface covering may also be of the type of laminate or vinyl flooring or wallcovering (e.g., in the form of tiles, planks or rolls). It may comprise a wear layer as the use-surface layer and the one or more support layers may comprise one or more structural core layers. The wear layer may comprise a topcoat. The topcoat may comprise or consist of the antipathogenic crosslinked polymer material. The topcoat more preferably comprises or consists of antipathogenic crosslinked polyurethane and/or another antipathogenic crosslinked polymer. The wear layer may comprise a thermoplastic polymer, e.g., PVC. The wear layer and/or the topcoat are preferably transparent or at least translucent. [0021 ] The layer that comprises the antipathogenic thermoplastic or crosslinked polymer material, i.e. , the antipathogenic layer, may have antibacterial activity of 99% determined according to standard ISO 20743:2021. Additionally, or alternatively, the antipathogenic layer could show no growth of microorganisms (apparent under the microscope) according to standard ISO 846:2019. Additionally, or alternatively, the antipathogenic layer may have an antiviral activity of 99% determined according to standard ISO 18184:2019 and/or an antiviral activity of 99% determined according to standard ISO 21702:2019.

[0022] The antipathogenic layer may prevent microbial contamination over a time of at least 24 hours after surface cleaning. As used herein, “cleaning” designates the removal of foreign material (e.g., dust, soil, organic material such as blood, secretions, excretions, and microorganisms) from a surface. Cleaning does not necessarily kill germs, but by removing them, it lowers their number and the risk of spreading infection. In the context of flooring, cleaning preferably includes dry dust mopping and/or vacuum cleaning to remove dust and debris, followed by damp mopping with a detergent (water-soluble cleaning agent). It will be appreciated that a periodicity of cleaning of 24 hours (or less) is standard in healthcare or medical institutions. It will thus be appreciated that the concentration of antipathogenic agent may be adjusted in such a way that microbial contamination, especially biofilm formation, is prevented over the entire time interval between successive cleaning activities.

[0023] According to embodiments, the at least one of the one or more support layers comprises the antipathogenic thermoplastic or crosslinked polymer material. The antipathogenic thermoplastic or crosslinked polymer material could comprise a plastisol.

[0024] Preferably, the antipathogenic agent is selected to destroy, deter, render harmless, prevent the action of, and/or otherwise exert a controlling effect on, any pathogen exclusively by physical or mechanical action. In particular, the antipathogenic agent does preferably not act by release of substance (e.g., ions or molecules) exerting a chemical action on pathogens. The antipathogenic thermoplastic or crosslinked polymer material thus preferably comprises no biocidal product as defined in Article 3 of Regulation (Ell) No 528/2012 of the European Parliament and of the Council of 22 May 2012 concerning the making available on the market and use of biocidal products. [0025] According to embodiments, the release of antipathogenic agent from the decorative surface covering, measured in accordance with the antipathogenic agent release test (APART) described hereinafter is below 0.5 mg/kg.

[0026] In the present document, the verb “to comprise” and the expression “to be comprised of” are used as open transitional phrases meaning “to include” or “to consist at least of’. Unless otherwise implied by context, the use of singular word form is intended to encompass the plural, except when the cardinal number “one” is used: “one” herein means “exactly one”. Ordinal numbers (“first”, “second”, etc.) are used herein to differentiate between different instances of a generic object; no particular order, importance or hierarchy is intended to be implied by the use of these expressions. Furthermore, when plural instances of an object are referred to by ordinal numbers, this does not necessarily mean that no other instances of that object are present (unless this follows clearly from context). When this description refers to “an embodiment”, “one embodiment”, “embodiments”, etc., this means that the features of those embodiments can be used in the combination explicitly presented but also that the features can be combined across embodiments without departing from the invention, unless it follows from context that features cannot be combined.

Brief Description of the Drawings

[0027] By way of example, preferred, non-limiting embodiments of the invention will now be described in detail with reference to the accompanying drawings, in which:

Fig. 1 : is a schematic view of the structure of a carpet in accordance with an embodiment of the invention;

Fig. 2: is a cross-sectional schematic view of a flooring panel in accordance with an embodiment of the invention;

Fig. 3: is a diagram of test results showing the absence of migration of antipathogenic agent;

Fig. 4: is a schematic perspective view of sheet flooring in accordance with an embodiment of the invention during installation. Detailed Description of Preferred Embodiments

[0028] Fig. 1 schematically illustrates a decorative surface covering, in particular, flooring in the form of a carpet 10. The carpet 10 comprises plural layers, including: a pile layer 12, a primary backing layer 14, a precoat layer 16 and a secondary backing 18. Secondary backing layer 18 may include a structural core layer 20, a glass scrim layer 22 and a fleece layer 24. One or more of the above layers 12-24 may comprise or consist of an antipathogenic layer.

[0029] The pile layer may, advantageously, comprise or consist of PA (e.g., PA66 or PA6), PE, PET or PP yam. The primary backing 14 may consist of a fleece, e.g., a polyester fleece. The yam of the pile layer 12 may be attached to the primary backing layer by the precoat layer 16. The pile layer 12, the precoat layer 16 and/or the primary backing layer 14 may comprise an antipathogenic agent, preferably an antipathogenic agent targeting viruses and/or bacteria.

[0030] The secondary backing layer 18, in particular the core layer 20, the glass scrim layer 22 and/or the fleece backing layer 24 may also comprise an antipathogenic agent, preferably an antipathogenic agent targeting fungi and/or bacteria.

[0031 ] Each antipathogenic layer may include the same or a different antipathogenic agent or combination of antipathogenic agents.

[0032] Optionally, only a fraction (e.g., 2%-60% by weight, preferably 5%to 40% by weight) of the pile fibers comprises an antipathogenic agent. When the pile layer comprises a mixture of fibers with and without antipathogenic agent, the material of the different fibers is preferably identical or at least substantially identical otherwise. In other words, the fibers with the antipathogenic agent preferably contain the same thermoplastic or crosslinked polymer material as the fibers without the antipathogenic agent.

[0033] The antipathogenic agent(s) may be bonded (e.g., covalently bonded) to the polymer chains and/or to any filler particles of the respective host thermoplastic or crosslinked polymer material. The bonds between the antipathogenic agent and the host thermoplastic or crosslinked polymer material may prevent migration, lixiviation and washing-off of the antipathogenic agent. The bonding may thus contribute to mitigating release of antipathogenic agent into the environment and to maintenance of antipathogenic action over prolonged time, e.g., over the lifetime of the carpet 10 (several years, e.g., 2, 5, 7, 10, 12, 15 or 20 years).

[0034] As an antipathogenic agent, Zn compound selected, e.g., from the group consisting of: zinc oxide, zinc acetate, zinc carboxylate, zinc acetylacetonate, zinc pyrithione, zinc salt of pyrrolidone carboxylic acid (ZnPCA), zinc pyrrolidone, zinc hydroxide, and mixtures thereof, may be preferred. The thermoplastic or crosslinked polymer material could comprise, e.g., from 0.01 to 0.15 wt%, preferably from 0.03 to 0.075 wt%, of zinc.

[0035] Preferred examples of carpets are summarized in the table below:

[0036] Textile floor coverings according to examples 1 to 5 may use a Zn compound as the antipathogenic agent. In the examples, Zn content in each antipathogenic layer may range from 0.01 to 0.15 wt% (with respect to the mass of the respective layer).

[0037] The antipathogenic layers of the textile floor coverings according to examples 1 to 5 may be tested to have an antibacterial activity of 99% according to standard ISO 20743:2021. The antipathogenic layers of examples 1 to 5 may also show no growth of microorganisms (apparent under the microscope) according to standard ISO 846:2019. The antipathogenic layers of the textile floor coverings according to examples 1 to 5 may also be tested to have an antiviral activity of 99% determined according to standard ISO 18184:2019 and/or an antiviral activity of 99% determined according to standard ISO 21702:2019.

[0038] In example 5, the synthetic fibers consisting of the antipathogenic polymer material may provide 50% of the specific surface area of the layer of pile.

[0039] Fig. 2 shows a “vinyl”-type flooring panel 30 according to an embodiment of the invention. The flooring panel 30 has a having a top surface 32, a bottom surface 34 and at least four sides. Fig. 2 shows a first side 36 and a complementarily shaped second side 38 in more detail. The first side 36 comprises a first connection profile featuring a tongue 40 and the second side 38 comprises a second connection profile featuring a groove 42. The first and second connection profiles are configured for mechanically engaging and interlocking with a second and a first connection profile, respectively, of another flooring panel of the same type.

[0040] The tongue 40 and the groove 42 are complementarily shaped, so as to enable a tongue-and-groove connection between neighboring panels. The groove 42 is delimited at its bottom by a base 44.

[0041 ] The flooring panel 30 may be of a layered structure and include a core layer 46 and a wear layer 48 arranged on the core layer. The core layer 46 may be rigid, semi-rigid or flexible. As in the illustrated embodiment, the core layer 46 and the wear layer 48 may sandwich a decorative layer 50 (e.g., a print layer). The wear layer 48 may in this case be transparent or translucent, so that the decor is apparent to the users. The decorative layer 50 could comprise a dedicated printing substrate carrying one or more ink layers. Alternatively, the decorative layer 50 could consist of ink layer(s) printed directly on the backside of the wear layer 48 or the top side of the core layer 46. A backing layer 52, e.g. , a felt or fleece layer, may be arranged on the bottom side 34 of the flooring panel 30.

[0042] The core layer 46 may comprise a first sublayer 46a of a first polymer material, a second sublayer 46b of a second polymer material atop the first sublayer 46a and a third sublayer 46c of the first polymer material atop the second sublayer 46b. The first and second polymer materials may comprise thermoplastic polymer resin (e.g., PVC resin), plasticizer and filler material. The first and second polymer materials may be of different formulations, which give them different properties, in particular different stiffness and/or antipathogenic properties. It may be worthwhile noting, however, that the core layer could, alternatively, comprise the same polymer material throughout its height. According to yet another possibility, the sublayers 46a, 46b, 46c could be of three different compositions. It may also be worthwhile noting that the core layer 46 may comprise one or more reinforcement layers, e.g., glass or fiber veils or grids.

[0043] The wear layer 48 preferably comprises a main layer 48a, e.g., made of transparent thermoplastic polymer material, such as, e.g., transparent PVC, and a transparent topcoat 48b, e.g., made of a crosslinked polymer material, such as, e.g., radiation-cured polyurethane.

[0044] The wear layer 48, the core layer 48 and/or the backing layer 52 (possibly also the decor layer 50) may comprise an antipathogenic agent. According to a preferred embodiment, the topcoat 48b consists of a antipathogenic layer based upon a crosslinked polymer. Such topcoat-forming antipathogenic layer preferably targets viruses and/or bacteria. Additionally, or alternatively, one or more of the sublayers of the core layer may also comprise or consist of an antipathogenic layer. Such core- antipathogenic sublayer(s) preferably target viruses and/or bacteria and/or fungi. Additionally, or alternatively, the backing layer 52 may also comprise or consist of an antipathogenic layer.

[0045] Each antipathogenic layer may include the same or a different antipathogenic agent or combination of antipathogenic agents. [0046] The flooring panel 30 may have an overall height in the range from 2 to 10 mm, preferably in the range from 2.5 mm to 6 mm, and most preferably in the range from 2.5 mm to 4.5 mm.

[0047] It may be worthwhile noting that a continuous-type flooring (e.g., provided in the form of rolls) could have the same layered structure as the flooring panel 30. When the flooring is conditioned in the form of rolls, no formfitting connection profiles are normally provided thereon (the edges are typically straight). Variants of the flooring panel of Fig. 2 may include tiles with or without the complementarily shaped connection profiles.

[0048] Each antipathogenic layer may comprise, as the antipathogenic agent, a compound selected from the group consisting of: a Ca compound, a Na compound, a K compound, an Mg compound, a Ag compound, a Cu compound, a Zn compound and a Ti compound. A preferred antipathogenic agent may be a Zn compound selected, e.g., from the group consisting of: zinc oxide, zinc acetate, zinc carboxylate, zinc acetylacetonate, zinc pyrithione, zinc salt of pyrrolidone carboxylic acid (ZnPCA), zinc pyrrolidone, zinc hydroxide, and mixtures thereof. Each antipathogenic layer could comprise, e.g., from 0.01 to 0.15 wt%, and more preferably from 0.03 to 0.075 wt%, of zinc.

[0049] Examples of flooring panels in accordance with preferred embodiments of the invention are indicated in the table below.

[0050] Fig. 4 illustrates continuous or “sheet” flooring 60 in accordance with a further embodiment of the invention. Continuous flooring 60 includes an antipathogenic layer that defined the use-surface 62. Continuous flooring 60 may be provided in the form of rolls 64. [0051 ] Examples of sheet flooring in accordance with the embodiment of Fig. 4 are detailed in the table below:

[0052] The antipathogenic layers of the floor coverings according to examples 6 to 13 may be tested to have an antibacterial activity of 99% according to standard ISO 20743:2021 . The antipathogenic layers of examples 6 to 13 may also show no growth of microorganisms (apparent under the microscope) according to standard ISO 846:2019. The antipathogenic layers of the floor coverings according to examples 6 to

13 may also be tested to have an antiviral activity of 99% determined according to standard ISO 18184:2019 and/or an antiviral activity of 99% determined according to standard ISO 21702:2019.

[0053] The floor coverings according to examples 6 to 9 and 11 to 13 (including an antipathogenic layer as the topcoat) may prevent microbial contamination over a time of at least 24 hours after surface cleaning. These floor coverings may thus be especially suitable in locations where a periodicity of cleaning of 24 hours (or less) is enforced, e.g., in healthcare or medical institutions or senior living facilities.

[0054] It will be appreciated that floor coverings according to the invention may contribute significantly to the wellbeing of patients, residents, and care-giving personnel of such institutions. In particular, the risk of spreading of nosocomial infections (also called: hospital-acquired infections or healthcare-associated infections) may be significantly reduced by installing flooring (and, possibly, wallcovering) in accordance with embodiments of the invention.

[0055] To make PVC material with an antipathogenic agent, one may start from vinyl chloride monomer. 100 g of vinyl chloride may be dispersed in a mixture of organic solvents comprising, e.g.: 50-65 wt.% acetone, 5-10 wt.% ethanol, 5-15 wt.% water, 5- 10 wt.% methyl alcohol, and 10-15 wt.% isopropyl alcohol so as to obtain a mixture with a total mass of about 2 kg. To this one may add a solution containing, e.g,: ZnPCA: 2-3 g, ZnO: 0.1 -0.4 g, Zn(OH)2: 0.4-0.6 g, zinc pyrrolidone: 0.4-0.7 g and zinc pyrithione: 0.4-0.7 g. Polymerisation may be carried out by heating the so-obtained mixture and adding a suitable catalyst.

[0056] The same or similar solution of Zn compounds may be used with other monomer solutions, e.g., of propylene, ethylene, etc. The reaction time may vary depending on the monomer, the catalyst and the chosen reaction temperature.

[0057] The polymer enriched with Zn may then be used as a masterbatch and blended with the corresponding Zn-free polymer to reach a desired concentration of Zn.

[0058] The antipathogenic layer(s) of the different embodiments and examples may be effective for controlling or eliminating the bacterial proliferation of Gram- and Gram+ bacteria, e.g., Staphylococcus Aureus, Escherichia Coli, Pseudomonas aeruginosa, Acinetobacter baumanii, Enterobacter cloacae, and Clostriudium difficile. The antipathogenic layer(s) may, additionally, or alternatively, be effective for controlling or eliminating the proliferation of pathogenic yeasts, e.g., Candida albicans, Candida tropicalis, Candida stellatoidea, Candida glabrata, Candida krusei, Candida auris, etc. It will also be appreciated that the antipathogenic action being based on physical and mechanical rather than on chemical action may reduce the risk of emergence and the effects of antimicrobial resistance, which types of pathogens causing nosocomial infections may display.

Antipathogenic agent release test (APART)

[0059] Samples of antipathogenic thermoplastic or crosslinked polymer material were prepared in the form of cylindrical disks having a diameter of 43 mm and a thickness (height) of 3.5 mm suitable for XRF (X-ray fluorescence) measurements. Apart from comparative samples, the samples may have the same composition as the antipathogenic layer of the decorative surface covering.

[0060] Release of antipathogenic agent from the samples may be monitored by XRF spectroscopy on an Epsilon 3x spectrometer from PanAlytical by integration of a characteristic spectral fingerprint. Tested samples included Zn as antipathogenic agent. Zinc release was monitored by integration of the Ka spectral line at 8.630 KeV.

[0061 ] The sensitivity and the detection limit of the spectrometer for the antipathogenic agent may be determined by preparing a series samples with several known concentrations of the antipathogenic agent.

[0062] Test measurements were carried out using a Zn compound in a PVC matrix. Cylindrical test samples were prepared with Zn contents of 0, 10, 25, 50, 100, 200, 450 and 990 mg/kg, respectively. XRF response was found to be linear as a function of Zn concentrations above 50 mg/kg. The samples with 10 and 25 ppm of Zn, respectively, produced responses not significantly different from that of the Zn-free sample. It was thus concluded that the XRF signal (expressed, e.g., in cps) could be assumed to be proportional to the Zn concentration in the range from 50 ppm to 1 g/kg, after subtraction of constant background and that the detection limit of the spectrometer was 50 ppm.

[0063] For the test, samples of the antipathogenic thermoplastic or crosslinked polymer material are prepared as described above (Z-samples). In addition, samples of the same polymer material but free from the antipathogenic agent are also prepared (T-samples). Each Z-sample is then stacked with a T-sample and compressed between two glass plates (1 kg load). The T-samples are subjected to XRF spectroscopy upon production, and several times during 16 days of being stacked with the Z-samples. The difference between the final XPS signal and the initial XPS signal indicates the quantity of antipathogenic agent having been released from the Z-sample to the T-sample.

[0064] The APART procedure was carried out using Z-samples containing a Zn compound in a PVC matrix. T-samples consisted of the Zn-free (but otherwise identical) PVC matrix.

[0065] Fig. 3 shows the XPS response of four different T-samples (T-1 , T-2, T-3, T-4) upon production (Day 0) and after different incubation times (Days 1-16). The hypothesis of Zn transfer from the Z-samples to the T-samples could not be verified.

[0066] The APART comprises a second test, wherein a Z-sample is fragmented into small pieces and sieved with a US mesh 60 sieve (having openings of 250 pm). 5 g of the sub-sieve fraction (-60 mesh) are and placed into 50 ml of distilled water for a time of 12 days. The XRF response of the distilled water is measured before and after incubation.

[0067] The second test was carried out with Z-samples containing a Zn compound in a PVC matrix. No lixiviation of Zn could be detected.

[0068] While specific embodiments have been described herein in detail, those skilled in the art will appreciate that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.