WO2019150142A1

WO2019150142A1 - Antimicrobial composite, process for its preparation and its use

Info

Publication number: WO2019150142A1
Application number: PCT/HU2018/050009
Authority: WO
Inventors: László JANOVÁK; Imre DÉKÁNY; Gábor SZECSKÓ; József MARÁZ
Original assignee: Sanex Pro Kft.
Priority date: 2018-01-30
Filing date: 2018-02-16
Publication date: 2019-08-08
Also published as: HUP1800035A1

Abstract

The invention relates to a composite, particularly polymer concrete comprising the following materials in a matrix: (i) as first component the substantially completely polymerized, crosslinked reaction product of the following materials: a) unsaturated polyester resin; b) one or more monomer capable for polymerization reaction with said polyester resin; c) initiator; as a second component ii) one or more filler(s); (iii) one or more, optionally hydrophobic antimicrobial additives of inorganic origin, in the nanometer primary size, wherein the antimicrobial agent is homogeneously distributed in the composite. The invention also relates to a process for the preparation of the composite and the use of the composite for the manufacture of without limitation, sanitary products and animal feeders.

Description

ANTIMICROBIAL COMPOSITE, PROCESS FOR ITS PREPARATION AND ITS USE

THE STATE OF THE ART

Composite materials, briefly composites or associated materials, are complex materials that are composed of two or more different combinations of materials with different that are separate from macro, micro or nanosizes to enhance useful properties and reduce adverse properties. The base material of the composites achieves better properties through the amplifier phase. The base material is called matrix, and the other elements are called second (or reinforcing) phase (Wikipedia).

The polymer concrete means a formable material, which is of high strength, has a polymeric binder, and contains a solid additive. The essential feature of polymer concrete is that it does not contain cement or cementitious material as a binder, but it contains a resin of natural or synthetic origin, artificial resin, that is polymers. The life span of the polymer concrete is longer than that of the conventional concrete prepared using a cement-based binder, it has better mechanical properties (eg compression, tensile strength), which allows it to be used as a building material.

For example, the Hungarian patent HU 222 897 B1 discloses a use of polymer concrete, where ducts, which can be slipped or can be walked on, that is, in some cases are mechanically exposed, are covered by prefabricated polymer concrete elements. According to the cited document, the polymer is made of polyester resin and quartz sand. The solution disclosed in the referenced document, other than the present invention, because of the nature of the technical aim set therein, does not mention the ensuring of the antibacterial effect for the applied polymer concrete.

Hungarian Patent Application P9802472 discloses paving profiles of polymer concrete, wherein for example, epoxy resin, polyester resin, polyurethane resin, thermoplastic resins or methacrylate resins are used to produce polymer concrete. As fillers, fine (sieved, ground or chemically produced) mineral fillers such as squeeze, calcium carbonate or grounded quartz or coarse grained sand, and calcites may be used. The solution disclosed herein, other than the present invention, does not mention the use of an antibacterial agent.

In case of certain applications e.g. for sanitary products, it may be important to have an antibacterial effect on the surface of the product concerned.

US 6242526 patent document discloses an antimicrobial polymer latex consisting of ethylenicaUy unsaturated acid as anion and a quaternary ammonium compound as a cation. In the document referred to, the quaternary amine compound provides for antimicrobial effect. U.S. Patent No. 9,363,993 discloses an antibacterial resin composition comprising a thermoplastic resin such as polyester resin, polyamide resin and an organometaUic compound. The organometaUic compound allows the metal ion to escape to the surface of the resin and remaining in the ion form to provide an antibacterial effect.

EP 2962858 European patent document discloses an antibacterial coating. The coating is made from a solidifying liquid formulation which, as an antibacterial agent, contains silver ion, and as a tackifier it contains a natural or artificial resin.

U.S. Patent No. 5,919,554 discloses a fiber reinforced polyester based composite, wherein the antibacterial activity is achieved with organic antibacterial agents. According to the description the antibacterial agents may include, for example, chlorinated phenolic derivatives. The disadvantage of the solution is that these agents may be released from the product, although these are non-toxic agents, but their release can cause undesirable environmental stress.

US Patent document No. 20170164609 discloses an antibacterial coating comprising binder, antibacterial agent, surfactant and nanoscale silica particles. Said binder is a siloxane oligomer-based material and the antibacterial agent is silver or silver-containing ceramics. The coating disclosed in the referenced document is intended to provide a touch panel for medical devices that can easily be contaminated by microorganisms during frequent contact.

US Patent document No. 6162533 discloses a hardened coating having an antibacterial effect. The coating material is an irradiation-curable acrylate resin. According to the description, a layer of adhesive material is also required for the use of antibacterial coating to provide adequate adhesion. According to the description, the antibacterial agent may be an organic or inorganic material, based on a working example, a silver based agent on a zirconium phosphate carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1: The IR spectra of the unsaturated polyester resin according to Reference Example 1 during the polymerization reaction in the wave number ranges of 400-4000 cm⁴ (A) and 850-1050 cm⁴ (B).

Figure 2: The light microscopic measurements of the rock-fines filler materials according to the Reference Example 2, used in certain embodiments of the polyester based polymer concrete according to the present invention (scale bar: 10 mm).

Figure 3: The weight % particle size distribution determined by a series of sieves of the rock-fines filler materials according to the Reference Example 2, used in certain embodiments of the polymer concrete according to the present invention.

Figure 4: The flow curves of the polymeric concrete according to Reference Example 3 (2 parallel measurements).

Figure 5: The evolution of the penetration depth values determined during the kinetic assay of Reference Example 4 during the formation of a polyester resin crosslink according to the invention.

Figure 6: The schematic illustration of the initial TiCh and Ag-doped TiCE

Figure 7: The TEM recording of the Ag-doped TiCh nanoparticles.

Figure 8: The absorption spectra of the initial TiCh, and Ag-doped TiCh, respectively.

Figure 9: The purification zones in the presence of various concentrations of Ag-TiCh nanodispersions in case of Escherichia coli test bacterial culture.

Figure 10: X-ray diffractograms of Ag-montmorillonite according to Example 6, in powder form. Figure 11: Absorption spectrum of the Ag-montmorillomte (CEC: 0.5 and 1) dispersions according to Example

6

Figure 12: The purification zones in the presence of various concentrations of Ag-montmorillonite nanodispersion in case of Escherichia coli test bacterial culture (CEC = 0.5).

Figure 13: The X-ray diffractograms of Ag-hectorite according to Example 7, in powder form.

Figure 14: The X-ray diffractograms of Ag-nanoparticles.

Figure 15: The absorption spectrum of Ag-hectorite (CEC: 0.5 and 1) dispersions according to Example 7.

Figure 16: The purification zones in the presence of various concentrations of Ag-hectorite nanodispersion in case of Escherichia coli test bacterial culture (CEC = 0.5).

Figure 17: The UV-Vis spectrum and photo of Cu nanodispersion according to Example 8 (diluted to 10 ppm).

Figures 18- A and 18-B: The TEM recording and size distribution of the Cu nanoparticles according to Example

8

Figure 19: The X-ray diffractogram of Cu-nanoparticles according to Example 8.

Figure 20. The UV-Vis spectrum and photo of the Au nanodispersion according to Example 9 (diluted to 50 ppm).

Figure 21: The TEM recording of the Au nanoparticles according to Example 9 (d = 13.95 + 2.7 nm).

Figure 22: The SEM recordings of microparticles formed by ZnO nanoparticles according to Example 10 at various magnifications.

Figure 23: Schematic diagrams of the initial ZnO and ZnO hydrophobised by surfactant molecules.

Figure 24. The TG and DTG curves of the initial ZnO and the ZnO hydrophobised by surfactant molecules.

Figure 25: The result of the antimicrobial test of polymer concrete samples containing Ag-nanoparticle according to Example 11, made in line with ISO 22196: 2011 standard.

Figure 26: Measurement results of the antimicrobial effect of the polymer concrete samples containing ZnO according to Example 12.

Figure 27: Antimicrobial efficacy of samples containing 0-10% by weight ZnO according to Example 12 and the number of seed counts determined on the samples.

Figure 28: The EDX recordings of samples containing the antimicrobial additive according to Example 13 as a function of increasing additive content (0.5-2%).

Figure 29: Perimeter values determined for polymer concrete surfaces with increasing amount of antimicrobial additives.

Figure 30: How curve of polymer concrete sample containing 2% additive content.

Figure 31: How curves of the initial concrete samples and those containing 2% additive concrete samples.

Figure 32: The change of the measured E. coli germ numbers on polymer concrete samples according to Example 14.

Figure 33. The change of the measured E. coli germ numbers on 2% additive-containing polymer concrete samples (repetition, reproducibility test) as in Example 14.

Figure 34. The change of the measured E. coli germ numbers on polymer concrete samples with polished surface.

Figure 35: The measuring of the antimicrobial effect of antimicrobial additive containing polymer concrete samples as a function on the concentration and time in case of Staphylococcus aureus bacteria. Figure 36: Measurement of antimicrobial effects of polymer concrete samples containing 2% antimicrobial additive in case of Enterococcus faecalis bacteria.

Figure 37: Photos of plants of Enterococcus faecalis bacteria of the surface of the control and polymer concrete samples containing 2% of antimicrobial additives.

THE PROBLEM TO BE SOLVED BY THE PRESENT INVENTION

The technical problem to be solved with the present invention is to provide an antimicrobial composite, preferably polymer concrete, which

(a) contains an amount of inorganic antimicrobial additive sufficient to achieve an antimicrobial effect, where antimicrobial activity is considered to be at least 5 log decrease in the germ number occurring during 24 hours of contact time;

b) and the antimicrobial effect of a product made of a composite, preferably a polymer concrete, is comparable to the life span of a product, i.e., the wear of the surface of a polymeric product does not diminish the antimicrobial effect.

THE DISCOVERY ACCORDING TO THE PRESENT INVENTION

The present invention is based on the discovery that the object of the present invention is achieved, if a composite, preferably a polymer concrete is prepared from a mixture, in which the antimicrobial agent is in a homogeneous distribution. In a matrix structure with known components known from the prior art and described below in details, the simple mixing of an amount of antimicrobial agent sufficient to achieve antimicrobial activity did not lead to the desired results: on the one hand, to achieve the composite of the present invention, which is technically feasible (moldable); on the other hand, to ensure the homogeneous distribution of the active ingredient. We had to discover that the otherwise known structure of the matrix structure would require that the additive be admixed in

(a) a specific quantity;

(b) in special size ranges;

c) and if necessary, in a hydrophobic form.

Thus, the amount of antimicrobial additive is of importance to the present invention. Such a quantity should be included in the composition of the present invention, which does not yet inhibit the product's moldability and usability, but already is able to provide the expected antimicrobial effect. It will be appreciated that if a small amount of antimicrobial additives are added to the resin, the plasticity and curing characteristics of the composite, especially a polymer concrete, will remain advantageous, but if the amount of antimicrobial additive is increased, this can result in higher viscosity, while the antimicrobial effect will result in shorter contact times. In order to ensure that the amount of antimicrobial effect does not only result in a moldable composite, but also ensures a homogeneous distribution, it has been found that the antimicrobial agent should be within the nanometer primary range. By way of other approaches: the conventional antimicrobial amounts of inorganic active agents, while providing for the disinfecting effect, inhibit moldability and do not provide antimicrobial effect until the life of the product, while the active ingredients in the nanoscale primer particle size (even in conventionally antimicrobial amounts) do not necessarily provide for the surface material density required for antimicrobial activity, due to the homogenous particle distribution. In this case, an increase in the amount of active ingredient would be required, which would again be at the expense of moldability. Alternatively, keeping the particle size in a conventional range which, in addition to preventing the moldability over a certain amount, due to the lack of a homogeneous distribution, prevents the maintenance of care-free antimicrobial effect throughout the product's lifespan. However, it has been discovered that there is a particle size and amount of active ingredient that meets the above three requirements:

(a) moldability;

(b) antimicrobial effect-strength; and

c) and the consistent antimicrobial effect that achieves product life-span at the same time.

With respect to the above contradictory parameters, extensive research has been carried out and as a result we have created our invention.

BRIEF DESCRIPTION OF THE INVENTION

1. A composite, preferably a polymer concrete comprising in a matrix:

i) as a first component, substantially completely polymerized crosslinked reaction product of the following materials: (a) an unsaturated polyester resin; (b) one or more monomer reacting in a polymerisation reaction with the polyester resin; (c) initiator;

ii) as a second component, one or more fillers;

iii) one or more antimicrobial additive agents of inorganic origin in the nanometer primary size range, said antimicrobial additive agent optionally being rendered hydrophobic,

wherein the antimicrobial additive agent is in homogeneous distribution in the composite, and is in the amount ranging from 0.0075 to 10% by weight, preferably from 1 to 5% by weight, more preferably 2% by weight, based on the weight of the first component.

2. The composite according to item 1, wherein the monomer is selected from the group consisting of olefinic compounds, vinyl- and vinylidene compounds, acrylic compounds, styrene, divinylbenzene, methyl methacrylate, ethyl methacrylate, vinyl ethers, preferably styrene.

3. The composite according to item 1 to 2, wherein the initiator is selected from the group consisting of peroxides such as dibenzoyl peroxide, methyl ethyl ketone peroxide, azo and diazo compounds, dimethyl toluene, azo-bis-iso-butyronitrile, diazo- aminobenzene, preferably methyl ethyl ketone peroxide.

4. The composite according to any of items 1 to 3, wherein the second component filler is selected from the group of the following natural or synthetic rocks: CaMg(CC> ) , dolomite grains; quartz sand; titanium dioxide; and aluminum trihydrate; marble and granite molds; micro glass balloon thixotropizing thickening agent; synthetic hydrophilic amorphous silica produced by flame hydrolysis; carbon nanotube; chopped synthetic and fibrous materials, in particular carbon and aramid fibers.

5. The composite according to any of items 1 to 4, wherein the filler has a particle size distribution such that 50% by weight of the filler is made up of particles smaller than 315 gm, or 60% by weight of the filler is made up of particles smaller than 45 gm. 6. The composite according to any of items 1 to 5, wherein the antimicrobial additive agent is selected from the group consisting of zinc oxide (ZnO), silver -doped titanium dioxide (Ag-TiCk), silver-doped montmorillonite, silver-doped hectorite, copper, gold.

7. The composite according to item 6, wherein the primary particle size of the antimicrobial additive agent is from 5 to 500 nm, preferably 50 to 200 nm, more preferably from 50 to 150 nm, for example 90-100 nm, 110-120 nm, 140-150 nm.

8. The composite according to any of items 1 to 7, wherein the antimicrobial additive agent is hydrophobised.

9. The composite according to any of items 1 to 8, wherein the antimicrobial additive is functionalized with surfactants or polymers, preferably with sodium dodecyl sulfate, sodium stearate, sodium lauryl sulphate, sodium dodecylbenzene sulfonate, sodium decylbenzene sulfonate functionalized or alkylated or alkylarylated, or functionalized with a polyethylene glycol derivative, silicone, or acrylic derivative.

10. The composite according to any of items 1 to 9, wherein

i) in the first component, the amount of monomer is about 20-50% by weight, preferably 25-40% by weight, preferably 25-35% by weight, based on the total weight of the unsaturated polyester resin and the monomer together; the amount of initiator is from 0.5 to 5% by weight, preferably from 1 to 3% by weight, more preferably 2% or 2.5% by weight, based on the total weight of the first component; and the polyester resin gives the remaining amount of the first component;

ii) the total amount of the first component is from 15 to 30 % by weight, preferably from 18 to 25 % by weight, more preferably to 18.5 % by weight based on the total weight of the composite, preferably polymer concrete; iii) the remaining amount of the composite is the filler material.

11. A process for the preparation of the composite according to any one of items 1 to 10, preferably a polymer concrete, said process comprising the steps of:

a) mixing the unsaturated polyester resin with viscous properties and the low molecular weight monomeric liquids in a suitable proportion as described above, and then adding the initiator to this system which initiates the polymerization of the polyester resin and the monomeric components, that is, the formation of a crosslinked macromolecule structure;

b) adding the second component simultaneously or subsequently to step a);

c) adding to the mixture obtained in steps a) or b) an additive antibacterial powder formulation with vigorous stirring;

d) homogenizing the mixture obtained in step c) by stirring an additional, preferably 10 to 15 minute vigorous (min. 600 rpm) stirring, until a uniform color and viscosity, homogeneous product is obtained;

e) optionally pouring the mixture obtained in step d) into the desired forms and allow the polymerization take place, i.e. obtaining from the viscous system a solid composite material taking the form the mold tool. 12. Use of the composite materials according to any of items 1 to 10, preferably polymer concrete materials for the preparation of products, in particular polymer concrete products, in particular animal feeders, sanitary ware, dishwashing trays, especially so-called“solid surface” dishwashing trays.

DETAILED DESCRIPTION OF THE INVENTION

The subject matter of the present invention is a composite, preferably a polymer concrete comprising the following components in a matrix: i) as first component a substantially completely polymerized, cured reaction product of the following materials: a) unsaturated polyester resin; b) one or more monomer reacting with the polyester resin; c) initiator; ii) as second component one or more fillers; iii) an additive with antimicrobial effect of inorganic origin, said additive being in the nanometer primary size range, and is optionally being rendered hydrophobic, where said antimicrobial agent is homogeneously distributed in the composite.

The composite of the present invention, preferably polymer concrete, is characterized in that the unsaturated polyester resin and the monomer are substantially completely polymerized, cross-linked, and the antimicrobial additive in the composite is homogeneously distributed.

The terms“composite” and“polymer concrete” according to the invention are used as in the introduction to the prior art.

In the present invention, the terms“first component” and“organic component of the polymer concrete” are used interchangeably.

For the purposes of the present invention, the terms “harter”,‘hardening agent” and“initiator” are used interchangeably and their meaning corresponds to the basic concept belonging to the knowledge of those skilled in the art.

For the purposes of the present invention, the terms“antimicrobial additive”,“antimicrobial agent” and“active ingredient” are used interchangeably and their meaning corresponds to the basic knowledge of the person skilled in the art.

For the purposes of the present invention, the percentage of antimicrobial agent is to be understood as calculated based on the total weight of said first component.

The organic raw material of the matrix of the first component of the antimicrobial composite, preferably a polymer concrete according to the present invention is an unsaturated polyester resin cross-linked with one or more monomers in the presence of an initiator. The term polyester resin is the basic concept of the state of the art in the present technology field.

According to the invention, the monomer used in the first component can be selected from the group consisting of olefinic compounds, vinyl and vinylidene compounds, acrylic compounds, styrene, divinylbenzene, methyl methacrylate, ethyl methacrylate, vinyl ethers. In a preferred embodiment of the invention, the monomer is styrene. Understanding the meaning of the materials in the prior art, as well as the choice of the suitable monomer in the light of the foregoing, belongs to the knowledge of a person skilled in the art.

According to the invention, the initiator used in the first component can be selected from the group consisting of peroxides (e.g. dibenzoyl peroxide, methyl ethyl ketone peroxide), azo and diazo compounds, dimethyl toluene, azo- bis-iso-butyronitrile, diazo-aminobenzene, but not limited to these. Preferably said initiator is methyl ethyl ketone peroxide. From the above-mentioned prior art, the understanding of the meaning of the materials and, in the light of the foregping, for the purposes of the invention, the choice of the appropriate initiator of the invention belongs to the knowledge of the person skilled in the art.

The polymerization mechanism of the unsaturated polyester resin according to the present invention was tested by infrared spectroscopic (IR) measurements as described in Reference Example 1.

The antimicrobial composite according to the present invention, preferably polymer concrete, comprises a filler as a second component. These fillers are commercially available natural or synthetic stone grate formulations, in particular, but not limited to, CaMg(CC> ) , fractions of various grates of dolomite (such as Betocarb products); quartz sand; titanium dioxide; aluminum trihydrate; marble and granite grates; micro glass balloon thixotropizing agent, thickening agent (e.g. products under Q-cell or Aerosil brands); synthetic hydrophilic amorphous silica produced by flame hydrolysis; carbon nanotube, which increases the mechanical strength, improves electrical, thermal and flammability properties; chopped synthetic and fibrous materials (e.g. carbon and aramid fibers). In the light of the foregoing, the choice of a suitable stone grate belongs to the knowledge of a skilled person.

Said filler’s particle size may be, for example, but without limitation, a rough fraction or a fine fraction. The said filler is not particularly limited in terms of particle size distribution, but may include, for example, 50% by weight of the filler material comprising particles of less than 315 pm or 60% by weight of the filler material comprising particles of less than 45 pm.

The antimicrobial composite of the present invention, preferably polymer concrete, further comprises an antimicrobial additive. Examples of said additive include zinc oxide (ZnO), silver-doped titanium dioxide (Ag-TiCti), silver-doped montmorillonite (Ag-montmorillonite), silver-doped hectorite (Ag-hectorite), copper, gold. Understanding the meaning of the materials mentioned herein belongs to the knowledge of the person skilled in the art. In a preferred embodiment of the present invention, the primary particles of the antimicrobial additive are nanoscale particles, i.e. the size of the primary particles of the antimicrobial additive falls in the nanometer size range.

In one embodiment of the present invention, the Z-average of the size of the primary particles of the antimicrobial additive is 5-500 nm, preferably 50-200 nm, more preferably 50-150 nm, for example 90-100 nm, 110- 120 nm, 140-150 nm. The Z-average used for the particle size determination based on light scattering means the mean hydrodynamic particle size (diameter) measured by the DLS (dynamic light scattering) method.

In preparing an antimicrobial composite of the present invention, preferably polymer concrete, the hydrophilic antimicrobial additive is dispersed in an organic polymer matrix. It has been found that in order to achieve an enhanced dispersibility in the composite such as in the resin of the polymeric concrete, it may be necessary to hydrophobize the starting hydrophilic particles, e.g. by functionalization with surfactant molecules or polymers. Suitable surfactants include, but are not limited to, sodium dodecyl sulfate, sodium stearate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium decylbenzene sulfonate. Suitable polymers include, but are not limited to, alkylated or alkylarylated polyethylene glycol derivatives, silicones, acrylic derivatives. Accordingly, in one embodiment of the invention, the particles of the antimicrobial additive are hydrophobized particles wherein the hydrophobic agent is a surfactant or a polymer. In a preferred embodiment of the invention, said surfactant is sodium dodecyl sulfate. The understanding of the meaning of the materials referred to herein, the recognition of the need for hydrophobisation, and the choice of the appropriate hydrophobic material belong, in the light of the foregoing, to the knowledge of the person skilled in the art.

According to the invention, the amount of monomer in the first component is about 20-50% by weight, preferably 25-40% by weight, preferably 25-35% by weight, based on the total weight of the unsaturated polyester resin and the monomer; the amount of initiator is from 0.5 to 5% by weight, preferably from 1 to 3% by weight, more preferably 2% or 2.5% by weight, based on the total weight of the first component; and the polyester resin yields the remaining amount of the first component. The choice of the exact amount of the initiator depends on environmental factors, such as temperature, but the choice of quantity belongs to the knowledge of the person skilled in the art.

According to the invention, the total amount the first component comprising the unsaturated polyester resin, the monomer and the initiator is from 15 to 30% by weight, preferably 18 to 25% by weight, more preferably to 18.5% by weight, based on the total weight of the composite, preferably polymer concrete.

According to the invention, the amount of antimicrobial additive is from 0.0075 to 10% by weight, preferably from 1 to 5% by weight, more preferably 2% by weight, based on the total weight of the first component comprising the unsaturated polyester resin, monomer and initiator.

In view of the foregoing, according to the invention, the remaining part of the composite, preferably polymer concrete (which is in each case, in the light of the above, supplemented to 100%) is the filler.

In the manufacture of polymeric concrete products according to the present invention, the inorganic fillers are mixed and dispersed into a polymer matrix of organic origin, to form a mixed composite material. Starting from this matrix, hydrophilic nanoparticles may be suitable as antimicrobial additives but the hydrophobic character of the nanoparticles of certain active ingredients may be required.

Another object of the present invention is a process for the preparation of the polymer concrete according to the present invention, comprising the following steps:

a) mixing the unsaturated polyester resin with viscous properties and the low molecular weight monomeric liquids in a suitable proportion as described above, and then adding the initiator to this system, said initiator initiates the polymerization of the polyester resin and the monomeric components, that is, the formation of a cured macromolecule structure;

b) adding the second component simultaneously or subsequently to step a);

c) adding to the mixture obtained in steps a) or b) an additive antibacterial in powder form with vigorous stirring; d) homogenizing the mixture obtained in step c) by an additional, preferably 10 to 15 minute vigorous stirring (min. 600 rpm), until a homogeneous product with uniform color and viscosity is obtained;

e) optionally pouring the mixture obtained in step d) into the desired molds and allow the polymerization to take place, i.e. obtaining a solid composite material from the viscous system to take the form of the mold tool.

The invention also relates to the use of the materials of the invention for the manufacture of products, in particular polymer concrete products, e.g. animal feeders, sanitary ware, etc. without limiting the invention to these products.

In the following, the invention will be illustrated by way of working examples, with no intention to be construed as a limitation of the invention.

EXAMPLES

Reference Example 1: IR spectroscopic assay of the polymerization of the polyester resin.

97.5% of the base material containing the unsaturated polyester resin and styrene was mixed with an amount of 2.5% initiator component. As the initiator, methyl ethyl ketone peroxide was used. During the polymerization, room temperature, normal atmospheric pressure and humidity were provided. The polymerization was monitored by infrared spectroscopy (IR) measurements. Through the polymerization mechanism, the double bonds in the polymer chains of the unsaturated polyester resin polymerize with the double bonds of the styrenic monomer to form the crosslinked structure. The resulting IR spectra were detected in the whole wave number (400-4000 cur¹) in Fig. 1A, and in Fig. IB we highlighted the polymerization-relevant (850-1050 cm⁴) wavelength range.

During the measurements, we investigated how the intensity of the double bonds of the unsaturated polyester resin and the styrenic monomer changes as a function of the binding time. According to the literature data, the peak characteristic of the polyester resin (-CH=CH-) is 982 cm⁴ and the peak characteristic of the vinyl group (CH =CH- ) in the styrene monomer is 912 cm⁴.

From the spectra shown in Figure IB, it can be seen that with the growth of the polymerization time, the intensity of both peaks is reduced, i.e. the unsaturated double bonds are consumed while polymerisation takes place. The process was followed every 20 minutes for 150 minutes. Finally, the spectrum of the sample was determined after 24 hours (Figure IB). It can be seen that after 24 hours the intensity of the peak (912 cm⁴) characteristic of the double bond binding of styrene has dropped to 0 while the peak (982 cm⁴) characteristic of the double bond binding of the unsaturated polyester resin is still present on the spectrum. Based on the results, the styrene monomer polymerized in 100% during the process, but due to the polyester resin, double bonds remain in the resulting crosslinked structure.

Reference Example 2: Test of the fillers.

The difference in size of the spherical particles is well visible in the light microscopic shots taken from the fillers used (dolomite stone particles, BETOCARB®) (Figure 2): larger aggregates can also be observed in the coarse fraction, while in case of the fine fraction particles well below 10 mm can also be seen.

A series of sieves was used to determine the particle size distribution of the samples. Figure 3 shows that the coarse fraction is composed ca. 50% by weight of particles of 315 gm or less, while the fine fraction is composed ca. 60% by weight of particles having a particle size of less than 45 gm.

As to their wetting properties, they are hydrophilic, as the water drops (methylene blue dye painted) put on the powder layer were completely spread on the surface of the samples.

Reference Example 3: Examination of the viscosity of the starting polymer concrete without antimicrobial effect.

Prior to the polymerization reaction, after the addition of the inorganic components, the viscosity of the initial polymer concrete was also determined by recording its flow curve. Rheological measurements were performed with an Anton Paar (Physica MCR 301) rheometer. During the measurements, a rheological tester CC27 (cylinder) and CC27 (sample holder) was used. During the measurements, the viscosity of the concrete samples was determined at 25 °C. Measurements were recorded at a deformation rate of 1 to 50 s . Figure 4 shows the flow curve of the polymer concrete sample. The viscosity of the flow curves was 2896.9 + 12.9 mPa*s. This measurement is important because the viscosity value that influences the pourability can be altered by the addition of the nanomaterial antimicrobial additive, and therefore it is of utmost importance for the present invention to retain the viscosity even after the addition of an antimicrobial agent in the still technically usable range according to this reference example.

Reference Example 4: Flardness test of polymer concrete during the polymerization.

The hardness of the polymer concrete formed during polymerization and curing was investigated as a function of the polymerization time. During the experiment we provided the parameters according to the operating conditions (room temperature, normal atmospheric pressure and humidity). During the measurements, 2% of hardener (harter) based on the resin component of the polymer concrete was added to the viscous polyester prepolymer component, and the viscous solution thus obtained was poured into sample holder jars, and samples of identical geometry and weight were placed in the resin at predetermined times.

Since the curing process is progressively forms the crosslinks during the polymerization reaction, this also means that the strength of the bulk phase sample, its hardness is constantly increasing with the polymerization time. As a result, the applied test specimens fell to a gradually lesser extent in the samples. The metal plates had a uniform size of 6.5x1.5x0.1 cm and a weight of 7.5 + 0.1 g. Fig. 5 shows the penetration depth values thus defined as a function of the polymerization time. It can be seen from the figure that the resin, in the conditions employed, approximately after 6 hours began to polymerize, and the process required 24 hours to complete.

The assay of the present example provides the technically expected hardness of the polymeric concrete, which must also be fulfilled after addition of the antimicrobial agent of the present invention.

Example 5: Preparation of nanoscale Ag-TiCk particles and examination of their antimicrobial activity.

During the synthesis of Ag-containing TiCk, silver nanoparticles-doped TiCk photocatalysts were synthesized according to the following prescriptions. During the production, 4 g of commercially available TiCk (Evonik) was dispersed in a mixture of 160 ml of distilled water and 40 ml of propanol. To the resulting slurry, 100 mM of AgNCk solution was added so that the Ag content based on the oxide was 0.5%. Subsequently, to achieve the photo reduction, the dispersion was illuminated for 1 hour with a Elamamatsu L8251 lamp (k_max> 280 nm, 150 W) for 1 hour, then centrifuged, washed 3 times with distilled water and dried to constant weight. As a result of the synthesis, an Ag-nanoparticle containing sample was obtained, in which ~ 10 nm Ag particles were located on the surface of 50 nm TiCk photocatalyst particles (Figures 6 and 7).

Subsequently, the optical properties of the prepared samples were examined. Fig. 8 shows the diffuse-reflection spectra of Ag-doped TiCk and the starting TiCk, respectively. It can be seen that in comparison with the initial TiCk, the Ag containing samples showed an absorption peak at l=440 nm, resulting from plasmon resonance of the Ag particles, proving that Ag-doped TiCk particles were actually generated.

Subsequently, various concentrations of Ag-TiCk dispersions were prepared for microbiological examination. The concentrations of dispersions were adjusted so that the concentration of Ag-nanoparticles on the surface of the Ag-TiCk particles would be 100, 75, 50, 25, 10, 5, 1 and 0.1 ppm, respectively. In the course of the microbiological studies, pre-set density (~ 106 CFU / ml) of Escherichia coli ATCC 29522 test bacterial suspension was prepared. Subsequently, 100 ml of the bacterial suspension was plated on Mueller-Hinton medium in Petri dishes having a surface of 50.2 cm² (Figure 9). Taking into account the above amounts, the bacterial surface concentration was 1.79x106 CFU/cm². 30 mΐ of the Ag-TiCk dispersion of different concentrations (Ag from 0.1 to 100 ppm) was pipetted to one quarter of the medium. Subsequently, the culture medium was incubated for 24 hours at 37 °C, and measuring the inhibition zones, the bactericidal activity of the test substance was determined. Knowing the size of the inhibition zones, the concentration of Ag-TiCk dispersion, the surface density of the Ag nanoparticles on the surface of Ag-TiCk nanoparticles can be determined, said value varied between 3 and 3000 ng/ cm² depending on the concentration (Figure 9). From the results, it can be seen that the Ag-TiCk nanoparticles inhibited the growth of the E. coli test bacteria having a surface concentration of 1.79 x 10⁶ CFU/cm² at a surface coverage of approximately 300-750 ng/cm², or above of said value, which is illustrated by the cleavage zones depicted in Figure 9. Based on the above results, it can be concluded that the Ag-TiCh also possesses antimicrobial properties.

Example 6: Preparation of Ag-montmorillonite and testing of its antimicrobial activity.

During the synthesis of Ag-doped montmorillonite, a 3 (w/V)% suspension from the initial Na-montmorillonite was prepared: 60 g of dry matter was measured into 2 liters of distilled water and the slurry was divided into two portions.

To the first portion of the suspension (to 1 liter of 3 (m/V)% suspension), a quantity of AgNCb (5.0010 g of AgNCb) sufficient to the montmorillonite cation exchange capacity (CEC: ~ 100 meq/lOOg) was added. To the second portion of the suspension (1 liter of 3 (m/V)% suspension) half the amount of AgNCb sufficient to the montmorillonite cation exchange capacity (2.5507 g AgNCb) was added. The two suspensions were thermostated for two days at 35 °C to adjust the ion exchange balance. Subsequently, both suspensions were centrifuged (for 40 minutes at 11,000 rpm) and then resuspended in 1 liter of distilled water. Silver nanoparticles were prepared by chemical reduction method using NaBEp as a reducing agent. Calculated amounts of NaBEp were added to the suspensions (Table 1) based on the following reaction:

AgNOs + NaBEp Ag + 1/2H₂ + 1/2B₂H₆ + NaNOs

(NaBH₄ + H₂0 NaBC>₂ +H₂)

1 30 3 5.1010 10.79 1.1357

2 _ 30 _ 3 _ 2.5507 5.39 0.5680

Table 1: The measured amounts during the preparation of the Ag-montmorillonite

The resulting Ag-montmorillonite slurry was dried by lyophilization after centrifugation (40 minutes at 11,000 rpm). The changes of the base-plate distance of the Na-montmorillonite and Ag-montmorillonite samples were compared with X-ray diffractogram measurements (Figure 10).

In Figure 10, the lowest diffractogram belongs to the initial Na-montmorillonite, while the other diffractograms belong to the Ag-montmorillonite samples produced at different cation exchange capacity. It can be seen that the peak of the original montmorillonite was 20=7.606° and 11.48 A base plate distance. These values are different for Ag-montmorillonite samples, indicating the intercalation of Ag particles between the supporting layers.

The resulting Ag-montmorillonite samples were sieved through a 90 mm sieve and resuspended in distilled water. For both samples 0.02 (m/V)% dispersion was prepared. Compared to the two Ag-montmorillonite samples (at the same concentration), it can be seen that a sample of 0.5 cation-exchange capacity was obtained with a much clearer, clear, transparent green dispersion, than in case of the dispersion corresponding to the cation exchange capacity (CEC:1). The absorption spectra of the two resuspended 0.02 (m/V)% Ag-montmorillonite dispersions were determined, as shown in Figure 11.

The absorption peaks of Ag-montmorillonite are visible at 1=390 nm due to the Ag particles present in the system. Subsequently, the dispersions were subjected to dynamic light scattering (DLS) measurements to determine the size of Ag-montmorillonite particles, as summarized in Table 2. Number

Z-average Zeta pot.

Samples

average

(nm) (mV)

(^nm)

Ag-mont. CEC: 0.5 93.99 0.405 13.61 -38.8

Ag-mont CEC: 1 140.40 0.358 18.71 -39.8

Table 2: The DLS measurement results of the Ag-montmorillonite dispersions

Subsequently, 100 ppm suspensions for the Ag content of the Ag-montmorillonite powder samples were prepared for further microbiological examination (Table 3). From the above suspensions of 100 ppm Ag concentration, dispersions of various concentrations (100, 75, 50, 25, 10, 5, 1 and 0.1 ppm) were prepared by dilution. The microbiological studies were performed as described in the previous section. From the results it can be seen that the Ag-montmorillonite nanoparticles (CEC = 0.5) at approximately 750-1500 ng/cm² or higher surface coverage, inhibited the growth of the E. coli test bacteria having a surface concentration of 1.79x106 CFU/cm², as illustrated by the cleavage zones depicted in Figure 13.

Samples m_measured (g) V (cm³) * c (ppm) **

Ag-mont. CEC: 0.5 0.2 100 100

Ag-mont. CEC: 1_ 01_ 100_ 100

*amount of the distilled water added to the weights measured in

“concentrations based on the Ag-content

Table 3: The measured amount in the preparation of the Ag-montmorillonite suspensions

Based on the above results, it can be concluded that the Ag-montmorillonite has antimicrobial properties.

Example 7: Preparation of Ag-hectorite and testing of its antimicrobial effect.

During the synthesis, 1.2 (w/V)% suspension from the starting hectorite was prepared by measuring 60 g of dry matter by adding 5 liters of distilled water. The resulting slurry was shared in two portions. To the first portion of the slurry (2.5 liter of 1.2% w/V suspension), a sufficient amount of AgNCfi was added to correspond the hectorite cation exchange capacity (CEC: ~ 100 meq/lOOg) (5.1010 g AgNCfi). To the second portion of the suspension (2.5 liters 1.2% w/V suspension), half the amount of AgNCfi corresponding to the cation exchange capacity was added (2.5507 g AgNCfi). Subsequently, both suspensions were centrifuged (for 40 minutes at 11,000 rpm). During centrifugation, in 1:1 proportion (pure 99.99%) ethanol was added to the suspensions to facilitate settling and more efficient centrifugation. It was then repeatedly resuspended in 2.5 to 2.5 liters of distilled water. Then, calculated amounts of NaBEfi were added to the suspensions (Table 4). The Ag-hectorite slurry thus obtained was centrifuged by the addition of 1:1 proportion of ethanol, followed by lyophilization. During centrifugation, in each case, the supernatant was collected and distilled by recovering a significant portion of the amount of ethanol added. Sample

1 30 1.2 5.1010 10.79 1.1357

2 30 1.2 2.5507 5.39 0.5680

Table 4: The measured amounts in the preparation of the Ag-hectorite

The base plate distances of the starting hectorite and Ag-hectorite samples were followed by XRD measurements (Figure 13).

In Figure 13, the lowest diffractogram belongs to the cation exchange capacity of the starting hectorite, while the other diffractograms belong to the various cation exchange capacity of Ag-hectorite. It can be seen that the peak characteristic of the original hectorite was 2Q = 6.380° with 11.745 A base plate distance. Different results were obtained for Ag-hectorite samples; the larger values of base plate distances indicate the intercalation of the Ag particles between the layers of hectorite. In the diffractograms observed at different cation exchange capacity of the Ag-hectorite another significant peak appears at 2Q = 38,102°, which indicates the presence of Ag-nanoparticles (Figure 14). In the X-ray diffractograms of the Ag-montmorillonite samples with various cation exchange capacity, the peak corresponding to the presence of Ag-nanoparticles can also be observed at 2Q = 38.102° (Figure 11).

The Ag-hectorite samples obtained were sieved through a sieve of 90 mm and dispersed in distilled water. For both samples a 0.02 (m/V)% dispersion was prepared.

Comparing the two Ag-hectorite samples (at the same concentration), it can be found that the sample having a cation exchange capacity of 0.5 resulted in a much clearer transparent yellow dispersion, while in case of the sample corresponding to the cation exchange capacity (CEC: 1) a darker yellow dispersion was obtained. The absorption spectrum of the two dispersed Ag-hectorite dispersions with 0.02 (m/V)% were also determined as shown in Figure 15.

The absorbance peaks of Ag-hectorite are close to l=390 nm due to Ag particles in the system, as was also observed in case of Ag-montmorillonite. The size of the Ag-hectorite particles in the two dispersed 0.02 (m/V)% dispersions was determined by dynamic light scattering (DLS), as summarized in Table 5.

Number

Samples Z-average _pdI Zeta pot.

average

r (nm) (mV)

(nm)

Ag-hectonte CEC: 0.5 110.36 0.322 16.53 -22.5

Ag-hectorite CEC: 1 96.99 0.399 23.86 -17.1

Table 5: The DLS measurement results of the Ag-hectorite dispersions

Based on X-ray diffractograms and absorption measurements, the Ag-nanoparticles are intercalated in the interlayer space in case of Ag-hectorite (as demonstrated by the increasing of the base plate distances, and the yellow colored dispersion).

Subsequently, 100 ppm suspensions as to their Ag content of Ag-hectorite powder samples were prepared for further microbiological examination (Table 6). The suspensions containing 100 ppm Ag concentrations above were made with different concentrations (100, 75, 50, 25, 10, 5, 1 and 0.1 ppm) of dispersions. The microbiological studies were performed as described previously. It can be seen from the results that the Ag-hectorite nanoparticles inhibited the growth of E. coli test bacteria having a surface concentration of 1.79x106 CFU/cm² at a surface coverage of 300- 750 ng/ cm², or above, respectively, as shown in the picture of Figure 16 of the cleavage patch zones.

Samples m measured (g) Y (cm³) * c (ppm) **

Ag-hect. CEC: 0.5 0.2 100 100

Ag-hect. CEC: 1 0.1 100 100

*amount of the distilled water added to the weights measured in

“concentrations based on the Ag-content

Table 6: The measured amounts in the preparation of the Ag-hectorite suspensions

Based on the above results, it can be concluded that the Ag-hectorite also has antimicrobial properties.

Example 8: Preparation of copper nanoparticles

The antimicrobial effect of Cu nanoparticles is well known in the literature. Valodkar et al. (M. Valodkar et al. Synthesis and anti-bacterial activity of Cu, Ag and Cu-Ag alloy nanoparticles: A green approach; Materials Studied Bulletin 46 (2011) 384-389] also synthesized starch-stabilized Cu (and Cu/Ag alloys of various composition) nanoparticles, and found that both the nano-Cu and the alloys exhibited antimicrobial properties based on the microbiological tests performed. As a test bacterium gram-negative, and Gram-positive E. coli and i^”. aureus strains were used. Lee et al. [Yong-Jung Lee et al. Morphology-dependent antibacterial activities of Cu20; Materials Letters 65 (2011) 818-820] demonstrated that the antimicrobial effect of Q12O nanoparticles depends from the morphology of said nanoparticles.

In the preparation of Cu nanoparticles, in the pre-prepared 200 ml of 1% starch solution such an amount of Cu (N0₃)₂.3H₂0 precursor (0.07604 g) was added that in the resulting product a Cu content of 100 ppm was obtained. Then, a calculated amount of NaBFL reducing agent was dissolved in 3 ml of distilled water and it was slowly added dropwise to the previously prepared solution. The reducing agent was added in a 30% excess. The resulting slurry was stirred for further 60 minutes until the reaction was complete.

The UV-VIS spectrum of the dispersion prepared is shown in Figure 17. The absorption spectrum of the slightly yellow Cu dispersion barely absorbs in the visible range, and as the wavelength decreases, the absorbance of the dispersion increases. The produced Cu sol samples were subjected to TEM measurement to determine the size of the particles contained therein. The results are shown in Figures 18-A and 18-B. In the TEM shots, the particles appear to be coated by the starch“mesh”, thus preventing the aggregation of copper nanoparticles, thus stabilizing the sol. Based on the results, the average particle size of the sample was 3.51 + 1.22 nm.

The structure of the obtained Cu nanoparticles was then examined by X-ray diffraction measurements (Figure 19). Based on the diffractogram we can conclude that in the dispersion the Cu occurs in a different oxidation state, as all of the elemental Cu, Cu (I) oxide and the Cu (II) oxide peak are present.

Example 9: Preparation of gold nanoparticles

It is also known from the literature that the Au-nanoparticles also possess antimicrobial properties. Arshi et al. (N. Arshi et al. Microwave assisted synthesis of gold nanoparticles and their antibacterial activity against Escherichia coli ( E . coli₎, Current Applied Physics 11 (2011) S360-S363] Au nanoparticles having a diameter of 1-6 nm were synthesized (at a concentration of 3400 ppm) using microwave irradiation. It was found that the duration of irradiation (40 and 70 s) has an effect on the size of the resulting nanoparticles. The produced Au-nanoparticles destroyed the E. coli test bacteria used.

In the preparation of Au-nanoparticles, in the pre-prepared 200 ml of 0.2% PVP polymer solution such an amount of HAuCb 3H2O precursor was added that the Au content in the resulting product was 100 ppm. Thereafter, a calculated amount of NaBEL* reducing agent was dissolved in distilled water and slowly added dropwise to the previously prepared solution. The reducing agent was added in a 30% excess. The resulting sol was stirred for further 60 minutes until the reaction was complete. The reaction was carried out at 90 °C.

The UV-VIS spectrum and the photo of the dispersion produced is shown in Figure 20. In the absorption spectrum of the red-colored Au dispersion there is one peak at l=513 nm due to plasmon resonance of Au nanoparticles.

The produced Au Sample was subjected to a TEM assay to determine the size of the particles contained therein. The results are shown in Figure 21. On TEM images, it appears that the Au nanoparticles in the dispersion are nearly spherical and have a homogeneous size distribution. The average particle size was 13.95 + 2.7 nm.

Example 10: Flydrophobicity of ZnO nanoparticles having antimicrobial activity

The starting ZnO nanoparticles were made hydrophobic with sodium dodecyl sulphate (NaDS) surfactant molecules, as these compounds have a negative charge due to the sulfate groups. Charge of the ZnO nanoparticles also changes by changing the pFl of the medium, but the isoelectric point of the nanoparticles is at 8.5.

The aqueous surface functionalization of the starting ZnO particles was performed at pFl=6. During the synthesis the ZnO/ surfactant ratio was 10/1. After the reaction, the medium of the resulting suspension was removed by spray drying. The SEM recordings of the resulting ZnO powder are shown in Figure 22. The images show that ZnO nanoparticles with ~15 nm primary particle sizes are formed. Based on our findings, the DS-ZnO particles thus produced were much more dispersed in styrene than the hydrophilic ZnO nanoparticles.

It can be stated, therefore, that on the basis of the mechanism shown in Fig. 23, ZnO particles having originally hydrophilic properties were hydrophobised. Thermogravimetrically measured NaDS content was 10.8%, which showed a good match with the measured surfactant content (10.5%) (Figure 24).

Example 11: Microbiological examination of silver nanoparticle containing polymer concrete samples

The purpose of the test is to determine the lowest antimicrobial additive concentration with microbiological standard qualification methods, where homogeneous compositional antimicrobial surfaces can be prepared, i.e., to find the concentration of active substances that complies with standard antimicrobial efficacy (5 log germ count decrease in 24 hours).

Our studies started with microbiological testing of the polymer concrete samples containing silver nanoparticle. The Ag content of the samples produced within laboratory conditions varied between 0.00125 and 0.5% by weight in accordance with Table 7.

Table 7: The Ag nanoparticle content of the antimicrobial polymer concrete samples, wherein K stand for control The aim of this study was to find out whether the samples treated with various active ingredients meet the basic requirements of EN 22196:2011 [Measurement of antibacterial activity on plastics and other non-porous surfaces].

Two important conditions have been taken: The sample should contact with a bacterial suspension of 1.5x105 to 5x106 CFU/cm² and the contact time is 24h.

In addition to the standard contact time required by the standard, a 4 hour contact time was also included, due to the target use of the samples.

According to standard strains, among the internationally accepted ATCC reference strains found in the Clinical Microbiology and Diagnostic Institute, the following test bacteria were selected: Escherichia coli ATCC 29522.

During the studies, physiological saline (0.85%) was used, which was sterilized in autoclave for 30 minutes at 121 °C and allowed to cool to room temperature before the test. The Petri dishes used during the test were sterilized for 20 minutes under UV light. Glass vials, glass rods and test tubes were heat-treated at 121 °C in an autoclave. The samples to be tested, the types of pipettes and the sample holders used during the test were kept under UV light (l=254 nm) for 1 hour. In setting the applied bacterial suspension, the Escherichia coli bacteria were removed from the stock culture by triple plating on BHI medium (brain and heart extracts medium) and incubated at 35 °C for 24 hours (according to EUCAST regulation). From the thus obtained culture, some isolated colonies were resuspended in 5 ml of physiological saline and McFarland value was measured. According to literature data, the 0.5 McFarland value for E. coli corresponds to 1.5x108 CFU/ml, so that the suspension is set to this value and then it was diluted to the 2.5x106 CFU/ml to 10x106 CFU/ml.

As a control, in most cases, a glass plate was used to look at the natural loss of bacteria (E. colt ) by examining whether there was any other factor outside the sample that would affect the viability of the bacteria (UV light, gas, temperature, humidity, etc.)

In the standard antimicrobial efficacy (ISO 22196: 2011) measurement, the previously sterilized (5 cm x 5 cm) samples were artificially infected with 0.4 ml of bacterial suspension (section 7.4 of the standard) and the bactericidal activity of the samples taken at different times (0, 24 h) was measured. For further contact time, the 4 hour incubation time was chosen. After the contact time elapsed, the samples were washed with 10 ml of sterile saline (section 7.6.1. of the standard) so that the surviving bacteria could be recovered from the test surface. 0.01 ml of the resulting slurry was plated on culturing medium, incubated at 35 °C for 24 hours and the result was evaluated by colonies and bacteria counts. For each sampling, a dilution line of 10 was made with 7 members and for each member we counted the number of colonies and the number of germs pertaining to the given area. The colony number was measured both manually and using a software (OPENCFU 3.9.0). The antimicrobial efficacy of the surface pertaining to the given time was calculated from the retransmitted values of the dilution series and their averages, based on the ten-based logarithm values according to the standard-defined method. The results were averaged from three parallel measurements and expressed together with standard deviations. Based on the measurement results shown in Table 8 and Fig. 25, it can be established that after 24 hours of contact time, samples with a silver concentration of >0.0075% and samples with a concentration of >0.25% after 4 hours of contact time decrease the number of germs by 5 log.

Table 8: The result of antimicrobial examination of silver nanoparticle containing polymer concrete samples according to ISO 22196:2011

Example 12: Microbiological examination of ZnO-containing polymer concrete samples

In this case, the synthesis of the polymer concrete samples containing the antimicrobial additive was carried out by dispersing ZnO nanoparticles instead of Ag nanoparticles into the continuous polymer concrete medium. In this case, the proportion of ZnO in the polymer concrete was 10% by weight.

As a reference, a polymer concrete sample containing the commercially available antimicrobial additive (NX- T O ) not in its body, but rather on its surface was also tested.

The microbiological examination of the polymer concrete samples thus prepared was carried out using standardized methodology as described in the previous example. From the results (Table 9 and Figure 26) we can see that after 24 hours of contact time, each sample had a 100% reduction in the number of germs. After 4 hours of contact time, the“wet” and“dry” samples had a 5 log number decrease.

Table 9: The results of the measurements of antimicrobial effect of ZnO-containing samples, the reference sample and the control sample

In possession of the above results, the synthesis and microbiological qualification of the samples were also performed by systematically reducing the former 10% by weight antimicrobial additive content. Thus, the additive content of the polymer concrete samples so produced was 0 (control), 2, 5 and 10% by weight, respectively. The microbiological qualification was carried out as described above. The results show that after 24 hours of contact time, in cases of the 2%, 5% and 10% samples a 100% decrease in the number of germs was demonstrated. After 4 hours of contact time, only 5 log germ number decrease was demonstrated for 10% samples (Table 10 and Fig. 27).

Table 10: Antimicrobial efficacy of samples containing 0 to 10% by weight ZnO and the germ number values determined on the samples

Based on the above results we can conclude that ZnO nanoparticles are suitable for the formation of antimicrobial polymer concrete. It has now been found that using a 2% by weight ZnO content, a sample that exhibits standard antimicrobial properties can be prepared under laboratory conditions.

Example 13: Production of polymer concrete with antimicrobial activity containing additive under operating conditions.

The aim of the study was to find out which is the smallest concentration of additives which is still sufficient to achieve antimicrobial properties. For this we have systematically changed the concentration of the additive in polymer concrete. Polymer concrete samples containing antimicrobial additives growing continuously from 0, 0.5, 1.0, 1.5 until 2.0% were prepared at SANEX Pro Ltd.'s plant by performing the following: 3000 g of polymer concrete base material, containing 18.5%, i.e., 555 g total weight of the first component, 11.1, 8.25, 5.5 and 2.77g of powdered antimicrobial additive, was added respectively, and the composite was homogenized with a mixing rod. The above concentration of the additive is thus based on the organic component of the polymeric concrete. If the additive content is calculated relative to the weight of the total composite polymer concrete, its concentration is 0.37; 0.275; 0.183; and 0.092% respectively, in the composite. After homogenization, polymer concrete samples were poured into templates and allowed to polymerize at room temperature. The resulting 5x5 cm² pieces were then taken to the lab the next day for examination.

The surface additive content of the samples was verified by energy dispersive X-ray spectrometry (EDX) measurements. In this process, the zinc oxide (ZnO) component of the additive was searched on the surface of the polymeric concrete samples. Figure 28 shows that increasing the concentration of the additive gradually increases the proportion of particles of ZnO, which increases the area loading of the antimicrobial additive on the surface. Due to this increased area loading, the perimeter values for the polymer concrete samples decreased relative to the baseline (additive- free) polymer concrete sample (Q=98.8°) (Figure 29).

In the next step, it was also investigated, how the added antimicrobial additive content influences the viscosity of the starting polymeric concrete. Figure 4 shows that the viscosity of the initial polymer concrete determined from the flow curves was 2896.9+12.9 mPa*s. Figure 30 shows the flow curve of the concrete sample containing 2% additive, while in Figure 31 the flow curves of the starting concrete and the sample containing 2% additive were illustrated together. The viscosity value determined from the flow curves was 6624.5+40.4 mPa*s for the 2% sample. In this way we determined the viscosity values of other polymer concretes as shown in Table 11. It can be seen that the measured values are almost linearly altered with increasing the antimicrobial additive content.

Table 11: Effect of antimicrobial additive content on viscosity values of polymer concrete samples

Example 14: Microbiological examination of polymer concrete samples with bacterium Escherichia coli.

Before the microbiological tests, the samples were kept at 70 °C for 4 days due to the styrene component evaporation, but after the microbiological tests, it was found that bacteria died also on the control sample. Subsequently, the samples thus were placed in an oven for another 4 days, this time storage took place at 120 °C. The results of the microbiological examination of the samples thus obtained are shown in Tables 12 and 13 and Figures 32 and 33.

Table 12: Measuring of the antimicrobial effect of polymer concrete samples containing antimicrobial agent for E. coli bacteria as a function of the active ingredient concentration and time

Table 13: Measuring of the antimicrobial effect of antimicrobial agent containing polymer concrete samples for E. coli bacterium in the case of a sample containing 2% additive (repetition, reproducibility test)

The results show that after 24 hours of contact time, the 0.5%, 1%, 1.5 and 2% samples showed a 100% reduction in the number of germs. After 12 hours of contact time, only the 2% samples showed a germ number decrease of 5 log.

The microbiological measurements were repeated for samples with 2% concentration. The previous results were also confirmed by the repeat test, with samples with a concentration of 2% additive, already having 5 log counts in the case of 12-hour contact. The above test series were also performed for polished samples, the results obtained are shown in Table 14 and Figure 33.

Table 14: Measuring of the antimicrobial effect of polymer concrete samples of polished surface with an antimicrobial agent for E. coli in the case of a sample containing 2% additive

On the basis of the measurement results, after a 24 hour contact period, 5 log decrease in the number of germs for each concentration occurred, which corresponds to the criterion established by the standard.

Example 15: Microbiological examination of polymer concrete samples with Staphylococcus aureus bacteria. The series of measurements presented in the previous example was also performed with Staphylococcus aureus (ATCC29523) as described in the standard. The results shown in Table 15 and Fig. 34 show that after 24 hours of contact time, the 1.5% samples were found to have ~40% germ number decrease and 100% germ number decrease for the 2% samples. After 12 hours of contact time, no acceptable decrease in the number of germs was achieved for any one of the concentrations.

Table 15: Measuring of the antimicrobial effect of polymer concrete samples containing antimicrobial additive as a function of the concentration and time in Staphylococcus aureus bacteria

Example 16: Microbiological examination of polymer concrete samples with Enterococcus faecalis bacteria.

The previous series of measurements were supplemented by testing a strain of human pathogenic bacteria frequently found in animal husbandry. Among the bacterial strains of zoonoses (animal-causing disease), the literature only mentions some as relevant strains that are highly dangerous to health. In animal husbandry, therefore tests and microbiological examinations specified to these species are used to qualify the various livestock farms and to establish the relevant regulations and hygiene regulations. These species include Escherichia coll, Staphylococcus aureus and Enterococcus faecalis, also referred to in the regulations and in the literature, which can cause serious infections or poisonings directly from the animals to humans or as foodstuffs (endo- and cytotoxins released from bacterial cells). Because of the above, we have chosen these strains as the basis for microbiological studies.

The bacterial suspension concentration was adjusted to the current water microbiology lab threshold (103 CFU/cm³), which corresponds to the concentration of Enterocccus sp. causing the infectious disease so that the antimicrobial effect of the treated surfaces can be determined with great certainty.

Microbiological tests were made on 2% samples showing antimicrobial efficacy according to the previous examples. From the results it can be seen that after 24 hours of contact time, the number of germs decreased by 100% for the 2% samples (Figures 35 and 36).

Based on the examples presented above, it can be concluded that the present invention has succeeded in achieving the intended technical goal. We have developed antimicrobial additives for polymer concrete based products, and operating scale technology to disperse the additive into the polymer concrete. It is important to emphasize that the additive is homogeneous in the product rather than being on its surface. As a result, the antimicrobial effect is comparable to the lifespan of the product and does not diminish its wear.

It has been shown that the primary particles of the additive in nanometer size range are uniformly distributed in the product by being made hydrophobic. Spatial loading of the particles increases with the concentration of the additive (0.5-2%) evenly. Addition of the additive to polymer concrete has a viscosity of 2896.9+12.9 mPa*s to 6624.5+40.4 mPa*s (sample containing 2% active ingredient).

The microbiological studies were performed according to International Standard ISO 22196:2011 (Measurement of antibacterial activity on plastics and other non-porous surfaces) for Escherichia coli and Staphylococcus aureus bacteria, and the tests were also performed on Enterococcus faecalis bacteria, which is not part of the standard, but considering the future applicability of the polymer concrete samples in animal husbandry and breeding, said strain was similarly relevant as the above. These species can cause serious infections or poisonings directly or as foodstuffs to humans (from endo- and cytotoxins released from bacterial cells), so we have chosen these strains as the basis for microbiological studies. On the basis of the results, after 24 hours of contact in case of the E. coli bacterium, there was a 100% decrease in the number of germs in the 0.5%, 1%, 1.5 and 2% samples. After 12 hours of contact time, only 5 log decrease in the germ counts occurred only in the 2% samples.

After 24 hours of contact with Staphylococcus aureus (ATCC 29523), in case of 1.5% samples ~40% and in case of 2% samples a 100% decrease in the number of germs was observed. After 12 hours of contact time, no reduction in the number of bacteria was observed for any one of the concentrations. For Enterococcus faecalis ATCC 29212 bacteria, the suspension concentration was adjusted to the current water microbiological laboratory threshold (103 CFU/cm3), which corresponds to the concentration of Enteroccus sp. causing infectious disease, such that the antimicrobial effect of the treated surfaces can be determined with great certainty. The microbiological tests were made on samples 2% previously showing antimicrobial efficacy. For a sample containing 2% additive, a 100% reduction in the number of germs occurred in 24 hours.

Based on the above, we can state that we have developed a raw material and technology for the production of antimicrobial polymer concrete under operating conditions. The 2% additive content of polymer concrete meets the requirements of ISO 22196:2011 standard, which requires 5 log reduction within 24 hours to determine the antimicrobial effect of the sample.

INDUSTRIAL APPLICABILITY

The present invention provides a solution for the production of antimicrobial polymer concrete and the production of sanitary products and animal feeders made of such polymer concrete. The polymer concrete according to the present invention comprises an antimicrobial additive in a homogeneous distribution, which ensures that the antimicrobial effect of the product of the polymeric concrete according to the present invention does not diminish with the wear of the surface of the product, so that the surfaces of the products need not be separately coated.

Claims

WHAT IS CLAIMED IS

1. A composite, preferably a polymer concrete comprising in a matrix:

i) as a first component, substantially completely polymerized crosslinked reaction product of the following materials: a) an unsaturated polyester resin; b) one or more monomer reacting in a polymerisation reaction with the polyester resin; c) initiator;

ii) as a second component, one or more fillers;

2. The composite according to Claim 1, wherein the monomer is selected from the group consisting of olefinic compounds, vinyl- and vinylidene compounds, acrylic compounds, styrene, divinylbenzene, methyl methacrylate, ethyl methacrylate, vinyl ethers, preferably styrene.

3. The composite according to Claim 1 to 2, wherein the initiator is selected from the group consisting of peroxides such as dibenzoyl peroxide, methyl ethyl ketone peroxide, azo and diazo compounds, dimethyl toluene, azo-bis-iso-butyronitrile, diazo- aminobenzene, preferably methyl ethyl ketone peroxide.

4. The composite according to any of Claims 1 to 3, wherein the second component filler is selected from the group of the following natural or synthetic rocks: CaMg(CC> ) , dolomite grains; quartz sand; titanium dioxide; and aluminum trihydrate; marble and granite molds; micro glass balloon thixotropizing thickening agent; synthetic hydrophilic amorphous silica produced by flame hydrolysis; carbon nanotube; chopped synthetic and fibrous materials, in particular carbon and aramid fibers.

5. The composite according to any of Claims 1 to 4, wherein the filler has a particle size distribution such that 50% by weight of the filler is made up of particles smaller than 315 gm, or 60% by weight of the filler is made up of particles smaller than 45 gm.

6. The composite according to any of Claims 1 to 5, wherein the antimicrobial additive agent is selected from the group consisting of zinc oxide (ZnO), silver -doped titanium dioxide (Ag-TiCb), silver-doped montmorillonite, silver-doped hectorite, copper, gold.

7. The composite according to Claim 6, wherein the primary particle size of the antimicrobial additive agent is from 5 to 500 nm, preferably 50 to 200 nm, more preferably from 50 to 150 nm, for example 90-100 nm, 110-120 nm, 140-150 nm.

8. The composite according to any of Claims 1 to 7, wherein the antimicrobial additive agent is hydrophobised.

9. The composite according to any of Claims 1 to 8, wherein the antimicrobial additive is functionalized with surfactants or polymers, preferably with sodium dodecyl sulfate, sodium stearate, sodium lauryl sulphate, sodium dodecylbenzene sulfonate, sodium decylbenzene sulfonate functionalized or alkylated or alkylarylated, or functionalized with a polyethylene glycol derivative, silicone, or acrylic derivative.

10. The composite according to any of Claims 1 to 9, wherein

11. A process for the preparation of the composite according to any one of Claims 1 to 10, preferably a polymer concrete, said process comprising the steps of:

b) adding the second component simultaneously or subsequently to step a);

e) optionally pouring the mixture obtained in step d) into the desired forms and allow the polymerization take place, i.e. obtaining from the viscous system a solid composite material taking the form the mold tool.

12. Use of the composite materials according to any of Claims 1 to 10, preferably polymer concrete materials for the preparation of products, in particular polymer concrete products, in particular animal feeders, sanitary ware, dishwashing trays, especially so-called“solid surface” dishwashing trays.