DE102008062125A1 - Suspension for treating filters or filter materials, methods of treating filters or filter materials, and filters or filter materials having a biocidal coating - Google Patents

Abstract

The invention relates to a suspension for the treatment of filters or filter materials and to a method for treating filters or filter materials and filters or filter materials having a biocidal coating. These filter materials are primarily used in air filters of air conditioning systems, including air heating and / or air cooling systems.

Description

The The present invention relates to a suspension for the treatment of Filters or filter materials and a method of treatment filters or filter materials and filters or filter materials with a biocidal coating. These filter materials are primarily in air filters of air conditioning systems, including systems used for air heating and / or air cooling. The application however, is not limited to these areas.

air conditioning in vehicles, homes, offices, cleanroom production facilities, medical facilities and other buildings included Air filter. The task of the filter is mostly air pollution, like the smallest solid particles, to separate from the air stream.

Often Activated carbon is integrated into the filter or as a separate activated carbon filter upstream or downstream to organic compounds from the air stream separate. The filter material can be very different Materials exist. For example, from natural Materials such as celluloses, inorganic materials such as glasses or ceramics and organic polymeric materials such as polyamide, Polyester or polypropylene.

The suspended in the filters and thus accumulated suspended matter from the air contain microbes and spores. During the Periods of high humidity or not operated filters are the conditions for the growth of pathogens such as bacteria, fungi, yeasts and viruses on this filter material very cheap. Many of these microorganisms will be not completely restrained by the filter and so get into the room to be ventilated and thus in contact with humans and other living beings.

The Filter material is also affected by microbial growth severely limited in its performance or even completely useless.

Of the Microbial growth leads to the release of endotoxins and mycotoxins, the metabolites of bacteria and fungi, with the air passing through the filter material. Endotoxins and Mycotoxins can be very harmful in humans Effects, e.g. Carcinogenic, mutagenic, or neurotoxic or cause allergic reactions.

The Reduction of microorganisms in filter systems, in particular air conditioning systems, and thus the spore germination also contributes to the risk for reducing illnesses and allergic reactions.

In the patent DE 101 22 753 A1 respectively. WO 2002 092890 A3 describes antimicrobial fibers which consist of polymer blends with at least one antimicrobial polymer and at least one other non-antimicrobial polymer. No inorganic biocides are listed. The biocides should be incorporated into the polymer, which severely limits biocidal activity in filter materials, especially air filters.

In the patent DE 10 2005 056 537 A1 describes a complex multilayer adsorption filter material with biological and chemical protection function, wherein the filter material consists of several layers with a catalytically active component and at least one adsorption layer and a carrier layer and a protective function against toxins and pollutants is to be achieved. Activated carbon acts as the adsorption layer. The layers with the catalytic components consist of a textile fabric in which metals or metal compounds are incorporated. The filter material is very complicated and serves primarily to protect against chemical and biological warfare agents and toxins. Another disadvantage is that it can only be used as a filter in one direction.

In the patent DE 601 20 943 T2 ( EP 1 269 088 B1 ) describes the equipment of an air filter with a water-soluble biostatic or biocidal agent. The duration of action of these water-soluble biostatic or biocidal agents is insufficiently short.

In the patent DE 10 2004 008 931 B4 the use of porous glasses, glass powders, glass ceramics or glass ceramic powders for receiving and dispensing substances or as absorbent of substances with and without filling claimed in cosmetics. However, the porous glass powders / glass-ceramic powders are phase-separated by tempering the glass with subsequent removal of at least one phase with an acidic solution, via a sintering process or via an organometallic or inorganic sol-gel process. The porous glass powder / glass ceramics are therefore not made of glass foam and an application in filter materials is not claimed.

In the patent EP 1 927 694 A1 For example, a method is claimed for antimicrobial finishing of fibers and / or textiles with desensitized silver components, which at the same time minimizes discoloration by the silver component. In this case, water-insoluble silver salts or in situ formed silver salt are claimed as the silver component. The "water-insoluble salts" release only very small amounts of silver ions. The release is further minimized by additional adjuvants for fixing the silver salt particles. Effective amounts of silver ions can thus be released only at full water saturation. No use of these fibers and textiles as filter material is claimed.

In the published patent application DE 10 2006 026 033 A1 a method for the production of antimicrobial or antibacterial glasses or glass ceramics is claimed, but no use in emulsions for coating filters or filter materials.

alternatives like membrane systems, which are to be understood as ceramics, have only one barrier function, that is the microorganisms remain on the membrane surface and starting from the accumulated yeasts and fungi can sprout even more spores get the air filter.

It is therefore an object of the present invention, a suspension for To provide treatment of filters or filter materials, which the previously described disadvantages of the prior art, at least largely avoids or at least mitigates. Furthermore It is an object of the invention, a suitable method for the preparation of biocidal filters or filter materials as well as to provide biocidal filters or filter materials that are mass produced as part of an industrial manufacturing process.

The The object of the invention is with a biocidal suspension with the Characteristics solved according to claim 1.

essential to the invention is that the suspension is at least biocidal, porous, amorphous, hydrophilic silver-containing glass powder made of extruded Contains glass foam and water.

It Extensive investigations were necessary to the essential Components of the suspension according to the invention to obtain.

The Subclaims 2 to 10 give advantageous embodiments without thereby limiting the invention.

Prefers in that the suspension according to the invention is 0.1 to 25% by weight, more preferably 1 to 10% by weight, biocidal, porous, hydrophilic, silver-containing glass powder, made of extruded glass foam, contains.

• – die porösen Glaspartikel des Glaspulvers aus Glasschaum von Silikat- oder Borosilikatgläsern bestehen,
• – die Gerüstdichte der Glasmatrix dieser Silikat- oder Borosilikatgläser zwischen 1,0 und 2,0 g/cm³ liegt und
• – die Durchmesser der Poren der Glaspartikel zur Einlagerung der Metallionen 1,0 × 10^–10 bis 20 × 10^–10 m betragen.

Preference is furthermore given to the biocidal, porous, hydrophilic silver-containing glass powder of extruded glass foam, wherein the silver is present in ionic form at least in a proportion of 40 to 100 percent by weight,

• The porous glass particles of the glass powder consist of glass foam of silicate or borosilicate glasses,
• The framework density of the glass matrix of these silicate or borosilicate glasses is between 1.0 and 2.0 g / cm ³ and
• - The diameter of the pores of the glass particles for incorporation of the metal ions 1.0 × 10 ^-10 to 20 × 10 ^-10 m amount.

The The object of the invention is also achieved by a method for the treatment of filters or filter materials with the invention Suspension with the features according to claim 11 solved.

a Another aspect of the invention relates to filters or filter materials with a biocidal coating having the features according to claim 13th

The Subclaims 14 to 19 give advantageous embodiments of the invention without limiting it.

Furthermore Uses of the invention in claims 20 to 22 discloses.

When Filter material is within the meaning of the invention that part of the filter to understand that filters out the impurities. A filter may consist of various filter materials, the filter materials, for example folded, connected or can be accommodated in a form and make the filter.

The antimicrobial suspension consists of porous, hydrophilic, amorphous, silver-containing glass powder and water. She can for the better Wetting of the filter material also contain surfactants. Furthermore Depending on the filter material is the use of other rheological additives possible, this being viscosity modifiers, Gelling or thickening agents can be.

the It is known to those skilled in the art that suspensions are mixtures of solids with a particle size of 1 μm to 1 mm and liquid are called. As a dispersion on the other hand, in chemistry mixtures of solids with a Particle size <1 μm and liquids. The biocides described here Glass particles contain subsets with a particle size <1 μm, but also glass particles with a particle size> 1 micron.

suspensions For the purposes of this invention also include dispersions with particle sizes biocidal, porous, amorphous, hydrophilic glass particles <1 μm.

The Suspension is made by mixing all components, taking with mixing also stirring, shaking, dispersing and other usual Process for preparing a suspension are prepared.

to Preparation of the suspension can be used drinking water. Prefers However, distilled water should be used as drinking water often contains chloride ions that affect the biocidal effect of silver ions to reduce.

The Suspension may contain rheological additives to the viscosity to modify so that a good distribution of the suspension up and / or in the filter or filter material is achieved. simultaneously However, a dripping of the suspension by use of the rheological Additives are minimized. The amount of rheological used Additive may vary depending on the chemical and physical Properties of the filter or filter material vary.

The Suspension may contain surfactants to better distribution of To achieve suspension on the filter or filter material or an impregnation of the filter and / or filter material. Surfactants in this context are the surface tension reduce the filter or filter material and a bead of the Prevent suspension. Depending on the surface properties of the filter or filter material may be anionic and / or nonionic and / or cationic and / or amphoteric surfactants used become.

The Antimicrobial long-term effect of the suspension is based on the diffusive release of the silver ions as well as the formation an alkaline environment by dissolving OH groups of the surface of the glass particles.

The porous biocidal glass particles contained in the suspension contain silver ions and silver nanoparticles, wherein the silver is present in ionic form in the porous glass particles at least in a proportion of 40 to 100 percent by weight. The porous glass particles are obtained by continuous foaming of silicate or borosilicate glasses by means of extruders. The framework density of the glass matrix of these glasses is between 1.0 and 2.0 g / cm ³ and the pore diameter for incorporation of the metal ions is 1.0 × 10 ^-10 to 20 × 10 ^-10 m.

in the Contrary to other solutions according to the Prior art, where that biocide incorporated into the filter material is the availability of antimicrobial agents when using the inventive method the surface of the filter material applied biocidal Suspension significantly higher.

Essential is that the diffusive release of silver ions and solution of OH ions from the glass particle surface then strongest although microbial growth is greatest is, namely at high humidity and high temperatures.

By the hydrophilic surface of the porous, amorphous Glass foam glass particles are absorbed by this humidity and the diffusive release of silver ions other non-hydrophilic carrier materials improved.

The for producing the glass foam and the porous, amorphous and hydrophilic glass particles used glass compositions may contain other metals that are bacteriocidal or ionic act fungicidal. These metals can be zinc in particular and copper.

in the Generally it is sufficient to know the amount of biocidal suspension such that bacteriostatic and fungistatic conditions arise on the filter material. However, it may be in individual applications also be necessary higher concentrations of biocides Suspension to kill the microorganisms on the filter.

The Amount of biocidal suspension applied to the filter material should be based on the filter material between 10 and 500 weight percent, preferably between 20 and 200 percent by weight.

Of the Silver content, calculated as metallic silver, of the suspension equipped filter or filter material should be between 10 and 5000 ppm, preferably between 50 and 500 ppm, wherein as reference the dry filter material is to be considered.

Of the used antimicrobial agent silver and the carrier material, porous, amorphous, hydrophilic glass foam glass powder, have a high environmental impact and are health largely unproblematic.

By the carrier material equipped with biocidal silver, Porous, amorphous glass powder made of glass foam, takes place good distribution of the biocidal silver in the suspension.

Under Filters are, without excluding other applications, in particular Air filter and surface filter to understand and in particular Air filters for air conditioning systems in vehicles and buildings.

Further Embodiments, modifications and variations of the present invention are for those skilled in reading the description without more recognizable and realizable without him doing the frame of the present invention leaves.

The The present invention will become apparent from the following embodiment However, which illustrates the present invention in no way limited.

A suspension of 100 ml of distilled water and 2.5 g of porous, amorphous glass powder (particle size: d ₅₀ = 3 microns, d ₉₉ = 20 microns) doped with 2.7% silver (trade name Trovo ^® guard) was prepared

One Car air filter (type KF 049 DE of the company Mann + Hummel; 300 x 99.5 x 30 mm) was mixed with this suspension impregnated by aerosol spray can. The filter was dried.

Out a car Audi A6 were the two after 30,000 km mileage Air filter removed (A1 and B1 in Table 1) and as a blank in terms of colonization with bacteria and mold, respectively for the raw air side (upstream) and the clean air side (downstream), examined. The results are included in Table 1.

Of the with the described suspension impregnated new air filters (A2 in Table 1) and as a comparative sample also a new air filter (B2 in Table 1) were installed in the car.

To another 30000 km mileage were taken from the two air filters and also on the colonization with bacteria and mold examined. The results are also included in Table 1.

The Sampling, as Abklatschprobe, took place by the nutrient media about 10 seconds with even pressure on the Filters were pressed.

It the following three different nutrient media were used:

1. Blood agar

In order to may be bacterial strains such as Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 12228), Streptococcus pneumoniae (ATCC 6301) Streptococcus pyogenes (ATCC 12344) Neisseria meningitidis (ATCC 13090) and Bacillus cereus (ATCC 11778) become.

2. Malt Extract Agar

With This nutrient medium is a humid environment simulated. By setting a low pH, the bacteria will grow inhibited. With this nutrient medium are occurring on wet surface or moisture-loving molds, such. B. Candida albicans (ATCC 10231), Aspergillus niger (ATCC 16404), Saccharomyces cerevisiae (ATCC 9763) and Saccharomyces uvarum (ATCC 9080).

3. DG 18 agar

DG 18 Agar is a dichloro-glycerol-18% agar with added chloramphenicol. Chloramphenicol addition inhibits bacterial growth. The contained 18% glycerin bind the water and serve as an energy source for the molds. The Dichloren inhibits fast-growing fungi, allowing even slow-growing species can be detected. Overall, with this nutrient medium molds the on dry surface (dryness-loving), such as Trichoderma longibrachiatum (ATCC 13631), Penicillium funiculosum (ATCC 9644) and also Candida albicans (ATCC 10231).

The culture media for the Abklatschproben were each 5 × 5 cm in size. In each case three samples were taken with each nutrient medium on the raw and clean air side of the filter. The data for the KbE (Colony Forming Units) contained in Table 1 are the sum of the three samples, thus refer to 75 cm ² filter area.

• KbE – Kolonie bildende Einheiten

The swab samples were then incubated at 20 and 36 ° C for the prescribed time periods, and then the number of colony forming units was determined. filter filterpage bacteria Molds moisturizing Molds dryness-loving in KbE / 75 cm ² in KbE / 75 cm ² in KbE / 75 cm ² untreated old air filter after 30000 km mileage (zero sample) A1 raw air 378 325 367 A1 clean air 98 247 302 B1 raw air 373 257 343 B1 clean air 98 134 250 new air filter treated with biocidal suspension after 30000 km mileage A2 raw air 352 590 352 A2 clean air 55 222 152 new air filter, untreated after 30000 km mileage B2 raw air 294 613 435 B2 clean air 127 302 313 Table 1: Load of Abklatschproben the car air filter with bacteria and molds

• KbE - colony forming units

The results of the swab samples in Table 1 show that the values for bacteria and the drought-loving molds are reduced to approximately 50% compared to the untreated filter (B2) due to the simple impregnation of the air filter with the suspension on the clean air side (A2) after 30,000 km mileage were. A comparison with the values of the previously used two untreated filters (A1 and B1) confirms these results. In the case of moisture-loving molds, the statement is not so clear, as Fil ter A1 and B1 were operated under other climatic conditions, which significantly fewer mold spores were found on the Rohluftseite. The air filters A2 and B2 used under the same climatic conditions also show differences on the clean air side. While the untreated air filter (B2) still analyzed 302 KbE / 75 cm ² on the clean air side, the filter (A2) treated with the suspension only had 222 KbE / 75 cm ² , with approximately the same values on the unfiltered air side.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10122753 A1 [0008]
• - WO 2002092890 A3 [0008]
• - DE 102005056537 A1 [0009]
• - DE 60120943 T2 [0010]
• - EP 1269088 B1 [0010]
• - DE 102004008931 B4 [0011]
• - EP 1927694 A1 [0012]
• DE 102006026033 A1 [0013]

Claims (22)

Suspension for the treatment of filters or filter materials, characterized in that the suspension contains at least biocidal, porous, amorphous, hydrophilic silver-containing glass powder made of extruded glass foam and water. Suspension according to claim 1, characterized in that that they contain 0.1 to 25 percent by weight, preferably 1 to 10 percent by weight, biocidal, porous, hydrophilic, silver-containing glass powder, made of extruded glass foam, contains. A suspension according to claim 1, characterized in that the biocidal, porous, hydrophilic silver-containing glass powder of extruded glass foam, wherein the silver is present in ionic form at least in a proportion of 40 to 100 weight percent, - the porous glass particles of glass foam of silicate or glass foam Borosilicate glasses exist, - the skeletal density of the glass matrix of the glass powder of these silicate or borosilicate glass is between 1.0 and 2.0 g / cm ³ and - the diameter of the pores of the glass particles for incorporation of the metal ions 1.0 × 10 ^-10 to 20 × 10 ^-10 m. Suspension according to claim 1, characterized in that from 40 to 99.5% by weight, preferably from 70 to 98% by weight, of water, particularly preferably distilled water. Suspension according to claim 1, characterized in that that one or more rheological additives are included and the rheological additives gelling agents, thickeners or others Means for modifying the viscosity. Suspension according to claim 1, characterized in that that rheological additives in amounts of 0 to 50 weight percent, preferably 2 to 10 weight percent are included. Suspension according to claim 1, characterized in that that one or more surfactants are included, this being anionic and / or nonionic and / or cationic and / or amphoteric surfactants are. Suspension according to claim 1, wherein one or more Surfactants in amounts of 0 to 50 weight percent, preferably 1 to 10 weight percent are included. Suspension according to claim 1, characterized in that that by dissolving OH-ions from the surface, also the pore surface, the porous, amorphous and hydrophilic glass particles, a biocidal effect is achievable. Suspension according to claim 1, characterized in that that from the glass matrix further metal ions, in particular zinc ions, which are a biocidal, especially a fungicidal Have effect. Method of treating filters or filter materials with a suspension, characterized in that it is a biocidal A suspension according to claim 1, which is characterized by a common coating method, such as spraying, Dipping or impregnating, applied and then drying takes place, producing a biocidal coating. Method of treating filters or filter materials according to claim 11, characterized in that the amount of on the filter or filter material applied biocidal suspension based on the weight of the filter or filter material between 10 and 500 weight percent, preferably between 20 and 200 weight percent, is. Filter or filter materials with a biocidal Coating, wherein the coating according to the method Claim 11 takes place and the coating at least partially biocidal, porous, amorphous, hydrophilic silver-containing Glass powder is made of extruded glass foam, and Other substances such as rheological additives and surfactants may be included can. Filter or filter materials according to claim 13, characterized in that they consist of chemical and / or natural and / or glass and / or ceramic and / or carbon fibers, preferably chemical fibers and a woven, knitted, knitted, nonwoven, non-woven Woven, scrim or a textile composite are or are out Fibers, threads, yarns, filaments or the like exist. Filter or filter materials according to claim 13, characterized in that all for the production of polymer fiber / filaments suitable macromolecules are components of the filter or of the filter material, in particular cellulose, cellulose acetate, Cellulose derivatives, wool, cotton, flax, ramie, silk, artificial silk, Aramid, polyamide, polyacryl, polyvinyl, polyvinylidene, polystyrene, Polyolefins, polyurethane, PTFE, polyethylene, polypropylene, polyester, Polyacrylonitriles, polyacrylic derivatives, polysulfones, polymethacrylates or mixtures of these. Filter or filter materials according to claim 13, characterized in that the fibers of the filter or filter material from a strongly moisture-binding polymer such as polyacrylic acid, partially neutralized polyacrylic acid and copolymers of Acrylic acid, acrylic esters, acrylamide and acrylonitriles consist. Filter or filter materials according to claim 13, characterized in that the silver content, as metallic Silver calculated, equipped with the biocidal glass particles Filter or filter material between 0.001 and 0.5 weight percent (10 and 5000 ppm), preferably between 0.005 and 0.05 weight percent (50 and 500 ppm), using as reference the dry Filter material applies. Filter or filter materials according to claim 13, characterized in that the biocidal effect in the reduction the colonization of the filter or filter material with microorganisms and reducing the number of microorganisms and spores in the filtered air (clean air) and the microorganisms bacteria, Yeasts and mushrooms are. Filter or filter materials according to claim 13, characterized in that this activated carbon as adsorption material contain. Use of a suspension according to claim 1 for antimicrobial coating of hard surfaces Plastic, glass, ceramics, wood, cork, stone, granite, marble, terracotta or metal. Use of a suspension according to claim 1 for subsequent coating and / or repeated renewed Coating filters or filter materials. Use of a filter or a filter material according to claim 13 for the purification of air and gas streams, in particular as a surface filter and air filter, preferably as air filters in air conditioning systems of vehicles.