Field of the invention

The invention relates to the antimicrobial surface treatment of vapor permeable foils or laminates, in particular antimicrobial surface treatments based on photoactive materials.

Background of the invention

Antimicrobial surface treatments are largely carried out through the additivation of industrial organic biocides. These biocidal substances exhibit a number of disadvantages associated with their basic properties. These are low-molecular substances used as additives for coating systems or directly for additivation into the mass. In a polymer system, these substances then have a tendency to migrate to the surface, and normal use leads to gradual wear and a reduction in their concentration. Biocidal products also exhibit a significant risk to ordinary users due to their high toxicological level. Their migration to the surface results in direct contact with the user who is then contaminated with this substance, which may lead to skin sensitization with the subsequent development of allergies or other dermatoses.

A considerable disadvantage of using industrial biocides is that their functional biocide component naturally migrates outside the protected polymer surface. It thus functions as a biocide not only directly on the surface of such a protected system, but also in the larger or smaller area of the surface. On one hand, this increases the risk of toxicological exposure for the user while on the other hand it increases the pressure to increase the concentration of the biocidal substance in the polymer matrix so that the long-term effective concentration of the biocidal component on the surface of the protected polymer is maintained for a long time.

Furthermore, biocides of this type usually do not exhibit broad effects, and because of their low activity against certain microbial strains a resistance gradually develops, resulting in an undesired increase in the occurrence of one specific type of strain at the expense of other strains. This will lead to a disruption of the natural balance between the different types of microorganisms and the subsequent uncontrolled massive increase in the concentration of microbial infection by one type of resistant microbial strain.

A new principle of protection from contamination by undesirable microorganisms is represented by photoactive substances called photocatalysts. These materials, after exposure to radiation of a defined wavelength, create highly reactive oxygen forms with a strong antimicrobial effect from diatomaceous oxygen. Additionally, limiting the access of radiation interrupts the creation of reactive oxygen forms, thus stopping the antimicrobial effect. The photoactive materials themselves are not toxic, so therefore they can be applied even in cases where there is direct contact with the user. This type of material includes, inter alia, the widely discussed titanium oxide. This material, after being affected radiation with a wavelength of 350 to 400 nm in the presence of oxygen and humidity, generates free radicals that are very active in the destruction of microbial contamination of such a treated surface. The disadvantage of this type of antimicrobial treatment is the high activity of free radicals against even organic materials. This leads to the destruction both of the organic materials adhering to the treated surface (self-cleaning effect) and the destruction of the carrier organic polymer, and also the destruction of the substrate material of an organic nature, in our case, the vapor permeable foil.

In addition to this type of photoactive material, a number of organic dyes have been proposed from the group of phenazines, phenothiazines, phthalocyanines, porphyrins, cyanines, chlorines, and naphthalocyanines which are sensitive to visible light, in this type of photoactive material, irradiation with visible light of 400 to 700 nm results in an interaction with oxygen which is its basic triplet state and also results in the subsequent generation of reactive forms of oxygen, particularly its singlet forms. Even though their lifetime is very short, they very actively attack microbial strains adhering to the treated surface, wherein the organic material polymeric nature is inert towards the effect of singlet forms of oxygen. The great advantage of this system is that so far no resistance towards this mechanism has been observed in any of the microbial strains. Reactive forms of oxygen have a broad effect on bacteria, yeasts, fungi and viruses. In the field of vapor permeable foils, there is a significant part of the production designed for sanitary and health purposes which require the foil to be sterile throughout the entire period of its use and without the release of hazardous substances from this material. During the use of commonly used foils, their surface becomes contaminated by microorganisms in the environment and their sterility therefore quickly disappears. Using industrial biocides to ensure the sterility of the foil surface is not possible, because these substances tend to release from the material surface and have negative effects on the environment.

The task of the invention is to create a vapor permeable foil or laminate with an antimicrobial surface treatment, which would be non-toxic and therefore suitable for use in the medical field, and permanent so it would be functional for the lifetime of the vapor permeable foil or laminate.

Summary of the invention

This task is solved by creating a vapor permeable foil or its laminate, possibly a laminate with nonwoven textiles, with antimicrobial surface treatment based on at least one photoactive material according to the submitted invention. The essence of the invention consists in the fact that on the surface of the vapor permeable foil there is arranged a thin film of the form of application comprising at least one photoactive compound of material sensitive to visible radiation in the wavelength range of 400- 700 nm, wherein the said compound is permanently bound to the surface of the vapor permeable foil or laminate. The advantage of this arrangement is that the photoactive materials provide antimicrobial protection exclusively on the surface of the vapor permeable foil and in no way affect the surrounding environment, and also that they provide for the long-term sterility of the material. The antimicrobial layer is always printed on the side of the vapor permeable foil. An essential condition of this arrangement is the prevention of migration or leaching of photoactive systems from the foil surface. This can be achieved by the photoactive substance being insoluble in water and hence not washing out, and having a large molecular weight and therefore not resulting in migration. A great advantage lies in the possibility of using materials, which are directly fixed in the system through the physical or chemical formation of a bond with a polymer matrix. Moreover, if a more intensive effect of the used photoactive materials must be achieved, their inhibitory effect can be increased through irradiation using a high power light source emitting radiation of a suitable wavelength.

Derivatives of phthalocyanines and porphyrins can be primarily used as highly efficient photoactive materials that meet the above conditions. Preferably these are the materials mentioned below, wherein the photoactive compound is comprised of at least one derivative of phthalocyanine or porphyrin, or a derivative of phthalocyanine containing, in the molecule, at least one functional group capable of forming a bond with a polymer matrix, especially of the amino-, hydroxy-, sulpho-, sulphanyl-, formyl-, hydroperoxy-, carboxy-, hydroxyamino-, hydrazino-, carbamoyl- group, and may also be in the form of amides, suiphamides, anhydrides, magnesium halides, phosphites, or a derivative of phthalocyanine comprising, in the center of the molecule, at least one bound metal from the group: Al, Ga, Zn, Si, or a derivative of nonmetal phthalocyanine.

Preferably, the phthalocyanine derivative is insoluble in polar and nonpolar solvents, and in the form of application it is contained as microparticles with a diameter of 50-500 nm.

In another preferred embodiment, the phthalocyanine derivative is insoluble in water and in the form of application it is contained in solution form in at least one polar solvent that is selected from the group: ethanol, propanol, butanol, ethyl acetate, 1- methoxy-2-propanol.

In another preferred embodiment, the phthalocyanine derivative is bound by a covalent bond in the structure of the polymer matrix creating the form of application.

In terms of production and the final price of vapor permeable foils, it is not advantageous to add the photoactive materials into the mass because of the high production costs, but also because of the risk of adverse physico-mechanical changes of these materials. For these purposes, advantageous would be a surface treatment of vapor permeable foils, laminates and nonwoven textiles; especially preferable is the use of printing techniques, such as flexography or gravure, or screen printing or inkjet printing. The form of application is thus a printing paste for printing the surface of permeable foils or laminate.

Finally, it is preferable that the thickness of the film on the surface of the vapor permeable foil or laminate is from 0.1 to 2 pm.

The advantages of the invention consist in the creation of an enduring film of the application comprising at least one photoactive compound on vapor permeable foils or laminates.

Examples of the preferred embodiments of the invention Example 1

Surface treatment of a vapor permeable foil with antimicrobial effects was carried out using zinc phthalocyanine without further substitution. This derivative of phthalocyanine is insoluble in polar and non-polar solvents, and the method of bead milling in ethanol was used to convert it to a microdispersion form containing 20% wt. phthalocyanine to increase its photoactivity. The median particle size was determined by laser diffraction at 300 nm. The dispersion was diluted at a ratio of 1 :1 with ethanol and additives to regulate viscosity, flow regulators, and film-forming agents to a consistency suitable for printing. The formulation thus prepared was applied to the foil surface using the flexography printing technique. The antimicrobial activity of the surface treatment was confirmed by testing for Escherichia coli bacteria under conditions simulating a normal room environment. The material, contaminated on the surface with bacteria, was exposed to 24 hours of radiation emitted from a normal energy-saving fluorescent lamp with a power of 15 W at 20°C and relative humidity 25-32%. The antimicrobial effect of the surface-treated vapor permeable foil was compared with the sample foil without surface treatment as a control. In comparison to the control, a decrease in the number of bacteria was noted by more than three orders of magnitude. Example 2

Antimicrobial surface treatment of a vapor permeable foil was carried out using a phthalocyanine derivative soluble in polar solvents usable for printing methods. A sulphamidic derivative of zinc phthalocyanine was converted into an ethanolic solution containing 2% wt. of the phthalocyanine derivative. The solution was applied to the foil surface using flexography printing techniques. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 3

The preparation procedure of surface treatment with antimicrobial effects is consistent with the procedure described in example 2 except that the phthalocyanine ethanolic solution was adjusted to a suitable consistency by adding a flow regulator and film forming agents. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 4

Antimicrobial surface treatment of a vapor permeable foil was carried out using a sulphamidic derivative of zinc phthalocyanine soluble in polar solvents. The phthalocyanine derivative was covalently bound to a polymer matrix based on acrylate, and the resulting phthalocyanine content in the dry polymer was 1% wt. A press formulation containing 50% wt. polymer in a solvent system ethanol - ethyl acetate - 1-methoxy-2-propanol was applied using the flexography method to the foil surface. The thus modified surface of the foil showed a decrease in the number of bacteria by 2 orders of magnitude.

Example 5

The procedure of preparation the surface treatment with antimicrobial effects is consistent with the procedure described in example 4, and the polymer matrix was used on a polyurethane base. The thus modified surface of the foil showed a decrease in the number of bacteria by 2 orders of magnitude. Example 6

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 2 except that the press formulation was applied using the gravure printing technique. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 7

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 3, except that the solvent used was 2-butanol and 1-methoxy-2-propanol. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 8

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 2, except that the solvent used was 2-butanol and 1-methoxy-2-propanol. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 9

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 2, except that the solvent used was 2-propanol and ethyl acetate. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 10

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 1 except that the press formulation was applied using the gravure printing technique. In comparison to the control, a decrease in the number of bacteria was noted by more than three orders of magnitude. Example 11

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 1 except that the press formulation was applied to a laminate consisting of a layer of vapor permeable foil and nonwoven layers, the surfaces of both of which were connected to each other by lamination, wherein the said surface treatment was carried out from the side of the vapor permeable foil. The antimicrobial effect of the coated laminate was compared with a sample of the laminate without surface treatment as a control. In comparison to the control, a decrease in the number of bacteria was noted by more than three orders of magnitude.

Industrial applicability

The vapor permeable foil or its laminate with an antimicrobial surface treatment according to this invention can be used for sanitary and health purposes and wherever the sterile nature of these materials is required.

Vapor permeable foil or laminate with antimicrobial surface treatment

Field of the invention

The invention relates to the antimicrobial surface treatment of vapor permeable foils or laminates, in particular antimicrobial surface treatments based on photoactive materials.

Background of the invention

Antimicrobial surface treatments are largely carried out through the additivation of industrial organic biocides. These biocidal substances exhibit a number of disadvantages associated with their basic properties. These are low-molecular substances used as additives for coating systems or directly for additivation into the mass. In a polymer system, these substances then have a tendency to migrate to the surface, and normal use leads to gradual wear and a reduction in their concentration. Biocidal products also exhibit a significant risk to ordinary users due to their high toxicological level. Their migration to the surface results in direct contact with the user who is then contaminated with this substance, which may lead to skin sensitization with the subsequent development of allergies or other dermatoses.

A considerable disadvantage of using industrial biocides is that their functional biocide component naturally migrates outside the protected polymer surface. It thus functions as a biocide not only directly on the surface of such a protected system, but also in the larger or smaller area of the surface. On one hand, this increases the risk of toxicological exposure for the user while on the other hand it increases the pressure to increase the concentration of the biocidal substance in the polymer matrix so that the long-term effective concentration of the biocidal component on the surface of the protected polymer is maintained for a long time.

Furthermore, biocides of this type usually do not exhibit broad effects, and because of their low activity against certain microbial strains a resistance gradually develops, resulting in an undesired increase in the occurrence of one specific type of strain at the expense of other strains. This will lead to a disruption of the natural balance

1 between the different types of microorganisms and the subsequent uncontrolled massive increase in the concentration of microbial infection by one type of resistant microbial strain.

A new principle of protection from contamination by undesirable microorganisms is represented by photoactive substances called photocatalysts. These materials, after exposure to radiation of a defined wavelength, create highly reactive oxygen forms with a strong antimicrobial effect from diatomaceous oxygen. Additionally, limiting the access of radiation interrupts the creation of reactive oxygen forms, thus stopping the antimicrobial effect. The photoactive materials themselves are not toxic, so therefore they can be applied even in cases where there is direct contact with the user. This type of material includes, inter alia, the widely discussed titanium oxide. This material, after being affected radiation with a wavelength of 350 to 400 nm in the presence of oxygen and humidity, generates free radicals that are very active in the destruction of microbial contamination of such a treated surface. The disadvantage of this type of antimicrobial treatment is the high activity of free radicals against even organic materials. This leads to the destruction both of the organic materials adhering to the treated surface (self-cleaning effect) and the destruction of the carrier organic polymer, and also the destruction of the substrate material of an organic nature, in our case, the vapor permeable foil.

In addition to this type of photoactive material, a number of organic dyes have been proposed from the group of phenazines, phenothiazines, phthalocyanines, porphyrins, cyanines, chlorines, and naphthalocyanines which are sensitive to visible light. In this type of photoactive material, irradiation with visible light of 400 to 700 nm results in an interaction with oxygen which is its basic triplet state and also results in the subsequent generation of reactive forms of oxygen, particularly its singlet forms. Even though their lifetime is very short, they very actively attack microbial strains adhering to the treated surface, wherein the organic material polymeric nature is inert towards the effect of singlet forms of oxygen. The great advantage of this system is that so far no resistance towards this mechanism has been observed in any of the microbial strains. Reactive forms of oxygen have a broad effect on bacteria, yeasts, fungi and viruses.

2 In the field of vapor permeable foils, there is a significant part of the production designed for sanitary and health purposes which require the foil to be sterile throughout the entire period of its use and without the release of hazardous substances from this material. During the use of commonly used foils, their surface becomes contaminated by microorganisms in the environment and their sterility therefore quickly disappears. Using industrial biocides to ensure the sterility of the foil surface is not possible, because these substances tend to release from the material surface and have negative effects on the environment.

The task of the invention is to create a vapor permeable foil or laminate with an antimicrobial surface treatment, which would be non-toxic and therefore suitable for use in the medical field, and permanent so it would be functional for the lifetime of the vapor permeable foil or laminate.

Summary of the invention

This task is solved by creating a vapor permeable foil or its laminate, possibly a laminate with nonwoven textiles, with antimicrobial surface treatment based on at least one photoactive material according to the submitted invention. The essence of the invention consists in the fact that on the surface of the vapor permeable foil there is arranged a thin film of the form of application comprising at least one photoactive compound of material sensitive to visible radiation in the wavelength range of 400- 700 nm, wherein the said compound is permanently bound to the surface of the vapor permeable foil or laminate. The advantage of this arrangement is that the photoactive materials provide antimicrobial protection exclusively on the surface of the vapor permeable foil and in no way affect the surrounding environment, and also that they provide for the long-term sterility of the material. The antimicrobial layer is always printed on the side of the vapor permeable foil. An essential condition of this arrangement is the prevention of migration or leaching of photoactive systems from the foil surface. This can be achieved by the photoactive substance being insoluble in water and hence not washing out, and having a large molecular weight and therefore not resulting in migration. A great advantage lies in the possibility of using materials, which are directly fixed in the system through the physical or chemical formation of a bond with a polymer matrix. Moreover, if a more intensive effect of the used

3 photoactive materials must be achieved, their inhibitory effect can be increased through irradiation using a high power light source emitting radiation of a suitable wavelength.

Derivatives of phthalocyanines and porphyrins can be primarily used as highly efficient photoactive materials that meet the above conditions. Preferably these are the materials mentioned below, wherein the photoactive compound is comprised of at least one derivative of phthalocyanine or porphyrin, or a derivative of phthalocyanine containing, in the molecule, at least one functional group capable of forming a bond with a polymer matrix, especially of the amino-, hydroxy-, sulpho-, sulphanyl-, formyl-, hydroperoxy-, carboxy-, hydroxyamino-, hydrazino-, carbamoyl- group, and may also be in the form of amides, sulphamides, anhydrides, magnesium halides, phosphites, or a derivative of phthalocyanine comprising, in the center of the molecule, at least one bound metal from the group: Al, Ga, Zn, Si, or a derivative of nonmetal phthalocyanine.

Preferably, the phthalocyanine derivative is insoluble in polar and nonpolar solvents, and in the form of application it is contained as microparticles with a diameter of 50-500 nm.

In another preferred embodiment, the phthalocyanine derivative is insoluble in water and in the form of application it is contained in solution form in at least one polar solvent that is selected from the group: ethanol, propanol, butanol, ethyl acetate, 1- methoxy-2-propanol.

In another preferred embodiment, the phthalocyanine derivative is bound by a covalent bond in the structure of the polymer matrix creating the form of application.

In terms of production and the final price of vapor permeable foils, it is not advantageous to add the photoactive materials into the mass because of the high production costs, but also because of the risk of adverse physico-mechanical changes of these materials. For these purposes, advantageous would be a surface treatment of vapor permeable foils, laminates and nonwoven textiles; especially preferable is the use of printing techniques, such as flexography or gravure, or

4 screen printing or inkjet printing. The form of application is thus a printing paste for printing the surface of permeable foils or laminate.

Finally, it is preferable that the thickness of the film on the surface of the vapor permeable foil or laminate is from 0.1 to 2 pm.

The advantages of the invention consist in the creation of an enduring film of the application comprising at least one photoactive compound on vapor permeable foils or laminates.

Examples of the preferred embodiments of the invention Example 1

Surface treatment of a vapor permeable foil with antimicrobial effects was carried out using zinc phthalocyanine without further substitution. This derivative of phthalocyanine is insoluble in polar and non-polar solvents, and the method of bead milling in ethanol was used to convert it to a microdispersion form containing 20% wt. phthalocyanine to increase its photoactivity. The median particle size was determined by laser diffraction at 300 nm. The dispersion was diluted at a ratio of 1 :1 with ethanol and additives to regulate viscosity, flow regulators, and film-forming agents to a consistency suitable for printing. The formulation thus prepared was applied to the foil surface using the flexography printing technique. The antimicrobial activity of the surface treatment was confirmed by testing for Escherichia coli bacteria under conditions simulating a normal room environment. The material, contaminated on the surface with bacteria, was exposed to 24 hours of radiation emitted from a normal energy-saving fluorescent lamp with a power of 15 W at 20°C and relative humidity 25-32%. The antimicrobial effect of the surface-treated vapor permeable foil was compared with the sample foil without surface treatment as a control. In comparison to the control, a decrease in the number of bacteria was noted by more than three orders of magnitude.

5 Example 2

Antimicrobial surface treatment of a vapor permeable foil was carried out using a phthalocyanine derivative soluble in polar solvents usable for printing methods. A sulphamidic derivative of zinc phthalocyanine was converted into an ethanolic solution containing 2% wt. of the phthalocyanine derivative. The solution was applied to the foil surface using flexography printing techniques. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 3

The preparation procedure of surface treatment with antimicrobial effects is consistent with the procedure described in example 2 except that the phthalocyanine ethanolic solution was adjusted to a suitable consistency by adding a flow regulator and film forming agents. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 4

Antimicrobial surface treatment of a vapor permeable foil was carried out using a sulphamidic derivative of zinc phthalocyanine soluble in polar solvents. The phthalocyanine derivative was covalently bound to a polymer matrix based on acrylate, and the resulting phthalocyanine content in the dry polymer was 1% wt. A press formulation containing 50% wt. polymer in a solvent system ethanol - ethyl acetate - 1-methoxy-2-propanol was applied using the flexography method to the foil surface. The thus modified surface of the foil showed a decrease in the number of bacteria by 2 orders of magnitude.

Example 5

The procedure of preparation the surface treatment with antimicrobial effects is consistent with the procedure described in example 4, and the polymer matrix was used on a polyurethane base. The thus modified surface of the foil showed a decrease in the number of bacteria by 2 orders of magnitude.

6 Example 6

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 2 except that the press formulation was applied using the gravure printing technique. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 7

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 3, except that the solvent used was 2-butanol and 1-methoxy-2-propanol. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 8

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 2, except that the solvent used was 2-butanol and 1-methoxy-2-propanol. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 9

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 2, except that the solvent used was 2-propanol and ethyl acetate. In comparison to the control, a decrease in the number of bacteria was noted by 1.1 orders of magnitude.

Example 10

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 1 except that the press formulation was applied using the gravure printing technique. In comparison to the control, a decrease in the number of bacteria was noted by more than three orders of magnitude.

7 Example 11

The procedure for preparation of surface treatment with antimicrobial effects is consistent with the procedure described in Example 1 except that the press formulation was applied to a laminate consisting of a layer of vapor permeable foil and nonwoven layers, the surfaces of both of which were connected to each other by lamination, wherein the said surface treatment was carried out from the side of the vapor permeable foil. The antimicrobial effect of the coated laminate was compared with a sample of the laminate without surface treatment as a control. In comparison to the control, a decrease in the number of bacteria was noted by more than three orders of magnitude.

Industrial applicability

The vapor permeable foil or its laminate with an antimicrobial surface treatment according to this invention can be used for sanitary and health purposes and wherever the sterile nature of these materials is required.

8