CZ309623B6 - An antimicrobial hydrophobizing liquid for surface treatment/protection of smooth non-absorbent materials containing methyl silicone resin - Google Patents

Abstract

The invention relates to an antimicrobial hydrophobizing liquid for surface treatment/protection of smooth non-absorbent materials containing methyl silicone resin dissolved in xylene. The proportion of methyl silicone resin is in the range of 15 to 70% by weight in the solution, which further contains nanoparticles and/or microparticles of metals and/or their oxides with antimicrobial properties in an amount of 0.001 to 8% by weight relative to the total solution for nanoparticles and in an amount of 0.1 to 8% by weight relative to the total solution for microparticles, wherein the size of the nanoparticles is in the range of 5 to 1000 nm and the size of the microparticles is in the range of 1 to 50 µm.

Description

Antimicrobial hydrophobizing liquid for surface treatment/protection of smooth non-absorbent materials containing methyl silicone resin

Field of technology

The invention relates to an antimicrobial hydrophobizing liquid for surface treatment/protection of smooth non-absorbent materials containing methyl silicone resin dissolved in xylene.

Current state of the art

Non-absorbent materials with a smooth surface are generally at less risk from exposure to moisture than absorbent materials. The danger is only if the surface is not hydrophobic and the liquid can remain on it, which allows it to contribute to destructive processes, especially corrosion in the case of metals or microbial degradation in other materials, during which certain microorganisms can produce corrosive compounds, for example sulfur oxidizing bacteria can create biogenic sulfane or sulfuric acid, or fungi and lichens can mechanically disturb the surface, for which, among other things, long-term moisture on the surface of the materials can provide a suitable environment for them.

The usual method of protecting materials against corrosion and other destructive phenomena is various varnishes, paints or paints that create a layer on the surface of the material and thus prevent its contact with the external environment, although their properties differ depending on the application. Their properties can also be modified using additives, for example the addition of metal microparticles or nanoparticles improves the antibacterial properties of the given coating.

CZ PV 2015-417 is a known hydrophobizing impregnation liquid with nano-additives for improving the hydrophobic and other useful properties of surfaces, which consists of an aqueous emulsion of methyl silicone resin with a minimum content of 15% by weight. silicone, while containing 0.1 to 60 wt.% thickeners in the form of lanolin and/or cetyl alcohol and nanoparticles of zirconium oxide ZrO2 in powder form and/or nanoparticles of silicon dioxide SiO2 in powder form and/or nanoparticles of titanium dioxide TiO2 in powder form and/or nanoparticles of aluminum oxide Al2O3 in powder form in a concentration of 0, 01 to 10.0 g/l starting aqueous methylsilicone emulsion, while the used nanoparticles of individual oxides in powder form have a size of 5 nm to 100 nm and can be used either individually or in their mutual combination. Hydrophobic treatment of the surface reduces the absorbency of the treated materials, which increases the lifespan and functionality of the products.

An alternative to varnishes and coatings can be, for example, the application of thin layers of materials with higher chemical resistance, antimicrobial properties or other advantages compared to the base material. An example can be, for example, chemical or galvanic nickel plating or the application of thin layers using methods using plasma.

At present, the great importance of antimicrobial treatments is also being shown, which prevents the contamination of surfaces with dangerous microorganisms, including bacteria, fungi or viruses. One of the ways to ensure antimicrobial properties is the application of layers of certain metals, especially silver, whose antimicrobial properties are the strongest of metals, or their oxides, or their nanoparticles or microparticles, which ensure antimicrobial properties by disrupting the electrostatic potential of cell membranes, creating reactive oxygen species , for example free radicals or hydrogen peroxide, and can also directly damage DNA or cause destructive mutations of these microorganisms.

The aim of the invention is to create a hydrophobizing liquid with antimicrobial effects for the surface treatment/protection of smooth non-absorbent materials.

- 1 CZ 309623 B6

The essence of the invention

The aim of the invention is achieved by a hydrophobizing liquid with antimicrobial effects for the surface protection of smooth non-absorbent surfaces of materials according to the invention, the essence of which is that the proportion of methyl silicone resin is in the range of 15 to 70% by weight. in a solution that also contains nanoparticles and/or microparticles of metals and/or their oxides with antimicrobial properties in an amount of 0.001 to 8 wt.%. relative to the total solution for nanoparticles and in the amount of 0.1 to 8 wt.% relative to the total solution for microparticles, wherein the size of the nanoparticles is in the range of 5 to 1000 nm and the size of the microparticles is in the range of 1 to 50 μm.

Metals and/or their oxides with antimicrobial properties are selected from the group consisting of silver, copper, nickel, zinc, titanium, iron, copper oxide, zinc oxide, titanium dioxide, and may be used alone or in combination.

Nanoparticles and/or microparticles of the above-mentioned metals and/or their oxides with antimicrobial properties are in powder form.

Nanoparticles of the above-mentioned metals and/or their oxides with antimicrobial properties can be in the form of a colloidal solution.

By adding up to 50 wt.% of water, an aqueous emulsion is formed.

The antimicrobial hydrophobizing liquid may further contain 0.1 to 60% by weight. thickeners, which are preferably formed by cetyl alcohol and/or lanolin.

To improve the tribological properties of the coating, the antimicrobial hydrophobizing liquid contains additions of hydrocarbons with a content of C6 to C14 in a concentration of 0.1 to 10 ml/l of the initial solution of methyl silicone resin in xylene or the initial aqueous methyl silicone emulsion, either individually or in mutual combination.

To further improve the useful properties of the coating, the antimicrobial hydrophobizing liquid contains the addition of ethyl acetate solution in the amount of 0.1 to 60% by weight. starting solution of methyl silicone resin or starting aqueous methyl silicone emulsion.

Examples of implementation of the invention

The antimicrobial hydrophobizing liquid according to the invention is based on methyl silicone resin dissolved in xylene and, if necessary, thickened with conventional thickeners, for example cetyl alcohol or lanolin. Nanoparticles and/or microparticles of at least one of the metals with antimicrobial properties, such as silver, copper, nickel, zinc, titanium, iron and/or their oxides, such as copper oxide, zinc oxide, titanium dioxide, are added to this solution. mutual combinations of nanoparticles and/or microparticles of these metals and/or their oxides are also possible. An aqueous emulsion can be formed by adding water to a solution of methyl silicone resin in xylene.

The antimicrobial hydrophobizing liquid contains a solution of methyl silicone resin dissolved in xylene, with a proportion of 15 to 70 wt.%. methyl silicone resins in a concentrated solution (resin + xylene + thickeners) or in a non-concentrated solution. The xylene solution of this resin can be used independently as a hydrophobizing coating, however, in order to add nanoparticles and/or microparticles in powder, it is advisable to thicken it with cetyl alcohol or lanolin, to limit the sedimentation of nanoparticles and/or microparticles, up to a content of 60 percent by weight of the thickener .

- 2 CZ 309623 B6

Nanoparticles and/or microparticles of metals and/or their oxides with antimicrobial properties are added to the solution in powder form in an amount of 0.001 to 8% by weight. relative to the total solution for nanoparticles and in the amount of 0.1 to 8 wt.% relative to the total solution for the microparticles, after which they are mixed thoroughly to ensure their uniform dispersion in the solution. This is true for both unconcentrated and concentrated solutions. The mixing method is arbitrary, only for ferromagnetic metals, especially iron and nickel, it is not suitable to use magnetic stirrers.

The particle size of metals and/or their oxides with antimicrobial properties ranges from 5 to 1000 nm for nanoparticles and from 1 to 50 pm for microparticles.

After applying the antimicrobial hydrophobizing liquid to the surface of the treated component, the liquid is able to harden even at normal room temperature. To achieve faster curing, heat treatment can be carried out, at least by drying at a temperature of at least 50 °C for at least 20 minutes. It is also possible to use firing at higher temperatures if the surfaces of thermally stable materials are being treated.

In the case of preparing an aqueous emulsion of a solution of methyl silicone resin in xylene, water is added for emulsification in an amount of up to 50% by weight. total weight of the resulting emulsion. This procedure also enables an alternative way to deliver nanoparticles into the resulting liquid, when instead of powdered nanoparticles, an aqueous solution of nanoparticles, a so-called colloidal solution, antimicrobial metals or their oxides, as well as their mutual combination, is used. The size of the nanoparticles again ranges from 5 to 1000 nm, and their concentration in the aqueous solution ranges from 0.01 to 20 g/l. The resulting emulsion must be homogenized.

Nanoparticles and microparticles further stabilize the emulsion, and emulsification prevents their sedimentation.

Liquids with microparticles, both emulsions and pure solutions, may be suitable to be stirred (homogenized) again before use, especially if sedimentation of microparticles occurs.

It is also possible to add a mixture of C6 to C14 hydrocarbons (hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane and tetradecane) to the mixture to further improve the water-repellent properties of the resulting liquid.

It is also possible to add a solution of ethyl acetate in the amount of 0.1 to 60% by weight to the mixture. relative to the weight of the original methylsilicone resin solution in xylene or the weight of the aqueous methylsilicone emulsion, to improve the useful properties of the resulting liquid.

Microparticles, nanoparticles, hydrocarbons and ethyl acetate can be used individually or in combination with each other.

In order to verify the feasibility of the composition and properties of the antimicrobial hydrophobizing liquid according to the invention, the following specific examples of liquids according to the invention were implemented, which serve to clarify the invention, not to limit it.

Example 1

To a solution of methyl silicone resin in xylene with a weight concentration of methyl silicone resin of 50% by weight. copper microparticles with a particle size of up to 10 µm were added with a mass fraction of 5 wt%. relative to a solution of methyl silicone resin in xylene. Subsequently, the solution was thoroughly mixed to ensure uniform dispersion of the particles in the solution.

The liquid prepared in this way must be thoroughly mixed before use, as the microparticles sediment quickly, but their significant aggregation does not occur.

- 3 CZ 309623 B6

Suitable methods of application of this antimicrobial hydrophobizing liquid are coating or spraying, and it is suitable for applications where abrasion or other risks of mechanical damage due to the poorer tribological properties given by the microparticles are not expected, and where equipment is available to mix the liquid before use, whether whether continuous or one-time just before use.

Example 2

5% by weight was added to the solution of methyl silicone resin in xylene according to Example 1. of cetyl alcohol and lanolin in a ratio of 1/1 relative to the basic solution of methyl silicone resin and 2 wt.% of copper microparticles up to 10 pm in size relative to the basic solution of methyl silicone resin in xylene. The solution was mixed thoroughly to ensure uniform dispersion of the microparticles in the solution.

Even the liquid prepared in this way should be thoroughly mixed before use, even though in this example the sedimentation of microparticles is slower than in example 1.

Application can be by spraying or painting, the liquid being usable for applications where abrasion or other risks of mechanical damage due to the inferior tribological properties given by the microparticles are not expected, and where equipment is available to mix the liquid before use, either continuous or disposable just before utilization.

Example 3

The antimicrobial hydrophobizing liquid is created from a solution of methyl silicone resin in xylene with a resin content of 50% by weight. and a colloidal silver solution in which the silver particle sizes range from 5 to 100 nm, with a mass concentration of silver of 50 mg/l. The proportion of the aqueous colloidal solution in the total weight of the liquid was 10% by weight, the proportion of methyl silicone resin in the resulting solution was therefore 45% by weight. The emulsion is then homogenized.

Nanoparticles do not sediment in the liquid prepared in this way, and the coating or spray has a higher abrasion resistance and is therefore suitable for applications where this resistance is needed.

Example 4

The antimicrobial hydrophobizing liquid is created from a solution of methyl silicone resin in xylene with a resin content of 50% by weight. and water, the proportion of which is 10 wt.% The proportion of methyl silicone resin in the resulting emulsion is therefore 45% by weight. Subsequently, the liquid is homogenized and 5% by weight is added to it. thickeners. Further, the liquid is modified by adding 1% by weight. of silver microparticles up to 20 pm in size and with the addition of hydrocarbons with a content of C6 to C14 in a concentration of 1 ml/l aqueous emulsion of methyl silicone resin. The emulsion is then homogenized.

The addition of hydrocarbons serves to improve the tribological properties of the coating or spray, and the silver nanoparticles are highly antimicrobial. The liquid prepared in this way is suitable, for example, for applications with high requirements for resistance to microbial contamination.

Example 5

The antimicrobial hydrophobizing liquid is created from a solution of methyl silicone resin in xylene with a resin content of 50% by weight. and water, the proportion of which is 10 wt.% The proportion of methyl silicone resin in the resulting emulsion is therefore 45% by weight. Subsequently, the liquid is homogenized and 3% by weight is added to it. thickeners. Furthermore, the liquid is modified by adding 0.1% by weight. of silver nanoparticles up to 100 nm in size. Into the water thus created

- 4 CZ 309623 B6 emulsion, a solution of ethyl acetate in the amount of 50% by weight is also added. aqueous emulsion and the emulsion is homogenized.

Silver nanoparticles show antimicrobial properties even at a minimum concentration, and ethyl acetate 5 serves to improve the useful properties of the coating or spray. The liquid prepared in this way is therefore again suitable for applications with higher requirements for antimicrobial properties.

Industrial applicability

The antimicrobial hydrophobicizing liquid according to the invention is intended for the treatment of non-porous materials with a smooth surface, ensuring their hydrophobicity and antimicrobial properties, while these properties are also achieved when drying at room temperature. By drying at an elevated temperature, a significantly faster drying time and a slight improvement in surface hydrophobicity can be achieved.

Claims (8)

1. Antimicrobial hydrophobizing liquid for surface treatment/protection of smooth non-absorbent materials containing methyl silicone resin dissolved in xylene, characterized in that the proportion of methyl silicone resin is in the range of 15 to 70% by weight. in a solution that also contains nanoparticles and/or microparticles of metals and/or their oxides with antimicrobial properties in an amount of 0.001 to 8 wt.%. relative to the total solution for nanoparticles and in the amount of 0.1 to 8 wt.% relative to the total solution for microparticles, wherein the size of the nanoparticles is in the range of 5 to 1000 nm and the size of the microparticles is in the range of 1 to 50 μm. 2. Antimicrobial hydrophobizing liquid according to claim 1, characterized in that the metals and/or their oxides with antimicrobial properties are selected from the group of silver, copper, nickel, zinc, titanium, iron, copper oxide, zinc oxide, titanium dioxide, either separately , or in combination. 3. Antimicrobial hydrophobizing liquid according to claim 2, characterized in that nanoparticles and/or microparticles of metals and/or their oxides with antimicrobial properties are in powder form. 4. Antimicrobial hydrophobizing liquid according to claim 2, characterized in that nanoparticles of metals and/or their oxides with antimicrobial properties are in the form of a colloidal solution. 5. Antimicrobial hydrophobizing liquid according to any one of claims 1 to 4, characterized in that it further contains 0.1 to 60% by weight. thickeners. 6. Antimicrobial hydrophobizing liquid according to claim 5, characterized in that the thickener consists of cetyl alcohol and/or lanolin. 7. Antimicrobial hydrophobizing liquid according to any one of claims 1 to 6, characterized in that it further contains hydrocarbons with a content of C6 to C14V in a concentration of 0.1 to 10 ml/l of a solution of methyl silicone resin in xylene. 8. Antimicrobial hydrophobizing liquid according to any one of claims 1 to 6, characterized in that it further contains ethyl acetate in an amount of 0.1 to 60% by weight. of a solution of methyl silicone resin in xylene.