DE102004028941A1 - Use of lithium ion containing aqueous solution (e.g. lithium hydroxide solution) for treating and preventing the growth of algae (e.g. green and red algae) and fungi on building surfaces, sculptures, gravestone (e.g. on the frontages) - Google Patents

Abstract

Method for treating and preventing the growth of algae and fungi on building surfaces, natural- and natural stonework surfaces, sculptures, gravestone (preferably on the frontages) comprises the use of lithium ion containing aqueous solution (preferably lithium hydroxide solution and mixture with lithium hydroxide solution). Independent claims are also included for: (1) a method for treating and preventing the growth of algae and fungi on building and sculptures (preferably concrete-, plaster- and natural stone- surfaces and surfaces) bearing paints or coatings comprising carrying out the method by spraying, flooding, immersing or painting; (2) a method for inhibiting the growth of algae and fungi comprising adding the lithium hydroxide in crystalline form (i.e. as lithium hydroxide, lithium hydroxide monohydrate or in other forms) to the paint or the plaster; and (3) a method for inhibiting the growth of algae and fungi on plaster comprising adding hydrate water free, lithium hydroxide or lithium hydroxide monohydrate or in other forms to the readily factory-made dry plaster mixture. ACTIVITY : Fungicide; Antialgal. MECHANISM OF ACTION : None given.

Description

The The invention relates to a method for controlling and preventing the Algae and fungal growth on building surfaces, sculptures and cemetery stones, especially on facade surfaces made of concrete, natural stone, natural stone or on plastered and coated Facade surfaces.

microorganisms especially algae and fungi, have always colonized the surface of Man-made artifacts, commodities and objects Buildings.

The intensity the settlement depends from the environment and thus growth conditions.

The Veralgung and z. T. fungaling of facades was still thirty years ago not a common problem that affects both the owner and Users of buildings, Sculptures and structures as well as product manufacturers and processors and those responsible for construction, such as planners and site managers.

First in the past twenty years, but increasingly in the last 15-10 years, had the massive increase in the growth of heavily weathered façade areas, in particular on plastered facades.

In The literature is becoming increasingly scarce about the alarming increase in algae production. and fungal growth on facades reported.

On almost all weathered areas and substrates algae growth (green or red algae) and fungal growth, usually in the form of black microfungi, detected.

A Set of strategies to combat and for prevention is suggested in the literature.

These Strategies are based either on physical measures, d. H. trying the surface to structure, or to provide hydrophobic by appropriate measures, so that in the following period the surface moisture balance is regulated can be that one Fouling by microorganisms is difficult or prevented.

One second strategy branch is based on the treatment of the affected surface with biocides, where the Long-term effect of these biocides is unsatisfactory. In addition, at The processing of these biocides is often a toxicological risk for humans and Environment received.

seaweed count (algae) to the plant organisms, which, single or multicellular, of microscopic Smallness up to a size of 50 m occur. The shape of the algae is spherical, flat, filamentous or tufted, unbranched or branched. They have real cell nuclei, mostly chlorophyll, often with brown, red ones or blue dyes covered. On facade facades or construction surfaces green algae like to settle down, Red and brown algae on.

seaweed are able to surfaces chemically and physically to influence and change. Therefore are algae-infested building surfaces not just as visual deficient, but as endangered consider.

to Propagation of algae requires sufficient moisture supply as well as light and carbon dioxide. Algae take over their cell walls in water dissolved nutrient on.

On Facade surfaces, especially plastered facade surfaces, grow next to the algae often Mushrooms.

These anchored in the plaster base in contrast to the algae. On the facade surfaces we often find so-called blackening fungi, in the case of suitable boundary conditions, for. B. the offer organic Substances and temperatures above 20 ° C, like them often on southern and west facades are to form a network of threads.

she anchor themselves underground, provide algae nutrients, so that symbiotic conditions for mushroom and algae are present.

• – so umweltfreundlich wie möglich ist
• – schwermetallfrei und
• – nicht durch Bewitterung auswaschbar ist
• – zu keinen bauschädlichen Nebenprodukten führt
• – die bauphysikalischen Merkmale des behandelten Materials nicht negativ beeinflußt
• – kapillar gut aufgesaugt wird
• – Algen und Pilze abtötet und dabei entfärbt, ohne die Struktur und den Farbton des Substrates signifikant zu verändern
• – sowohl in stark porösen als auch in feinporigen Untergründen aureichend tief eindringt und damit eine Wiederbesiedlung oder erstmalige Besiedlung durch Mikroorganismen, insbesondere Algen wie Grün- und Rotalgen sowie Pilze, insbesondere "Schwarzpilze" verhindert,
• – eine Depotwirkung besitzt.

The invention has for its object to perform a control and prophylaxis method using an algicidal and fungicidal agent of the type mentioned above, which

• - as environmentally friendly as possible
• - heavy metals free and
• - Can not be washed out by weathering
• - does not lead to any harmful by-products
• - The building physical characteristics of the treated material is not adversely affected
• - Capillary is sucked up well
• - kills and destroys algae and fungi without significantly altering the structure and hue of the substrate
• - In both strongly porous and in fine-pored substrates aureichend deeply penetrates and thus a repopulation or first colonization by microorganisms, especially algae such as green and red algae as well as mushrooms, especially "black fungus" prevents
• - has a depot effect.

The Task is solved by that according to the invention a lithium ion-containing Solution, preferably aqueous saturated lithium hydroxide solution in situ is used.

After this the previous strategies of control and prevention none satisfactory solutions show, especially from the point of view of long-lasting Effect, it was necessary for a possibility to seek to find a procedure and a substance that leads to one permanent solution leads.

To a preferred embodiment of Invention is the agent having a solids content, suitably more than 5% by mass at 20 ° C and preferably between 10 and 18% at 20 ° C used.

Procedurally so proceeded that the Means of flood or potion, better, however, in the coating process, is applied.

The latter serves to highly textured surfaces with the agent of the invention intensive contact. This treatment can also be repeated several times, z. B. two to three times be made.

The substance according to the invention can also be presented as a gel and applied.

Lithium compounds, In particular, lithium hydroxide, in many industries Fields used. In the construction industry, however, are lithium compounds only to a small extent for special applications used, such. B. lithium carbonate in toner cement-containing finished products like self-leveling compounds (floor filler) or lithium silicate as a plaster and stone strengthening material according to DE Patent No. 393299003.

For the film preservation of paints and coatings have been in the past halogenated phenol derivatives and heavy metal compounds used. These are because of their extremely polluting effect and the endangering of the consumer i. d. R. substituted by other classes of substances.

• – Harnstoff-Derivate wie z. B. Diuron,
• – Isothiazolinone wie z. B. 2-Octylisothiazolinon eingesetzt,
• – ferner Dithiocarbamatderivate wie Thiram oder Ziram mit Zink als Schwermetallionanteil,
• – Benzimidazolderivate wie Carbendazim oder Thiabendazol,
• – ferner Triazinderivate wie Irgarol 1051,
• – Benzothiazolderivate wie TCMTB,
• – Carbamidsäure-Derivate wie IPBC,
• – Thiophthalimid-Derivate,
• – Sulfensäure-Derivate,
• – Sulfon-Derivate,
• – Triazol-Derivate,
• – Pyridin-N-Oxid-Derivate

For the film conservation are currently

• - Urea derivatives such. Eg diuron,
• - Isothiazolinone such. B. 2-octylisothiazolinone used,
• Furthermore dithiocarbamate derivatives such as thiram or ziram with zinc as the heavy metal ion component,
• Benzimidazole derivatives such as carbendazim or thiabendazole,
• Further triazine derivatives such as Irgarol 1051,
• Benzothiazole derivatives such as TCMTB,
• Carbamic acid derivatives such as IPBC,
• - thiophthalimide derivatives,
• Sulfenic acid derivatives,
• - sulfone derivatives,
• - triazole derivatives,
• - Pyridine-N-oxide derivatives

Alles These active substances have their limits in the permanent moisture load such as B. weathering.

Further they are not as an aqueous solution, d. H. solvent-free and thus environmentally friendly to apply to a facade.

Aqueous lithium hydroxide solutions count in contrast to the aforementioned biocide solutions to the weakly water polluting Substances. Lithium hydroxide in low concentrations will even Used in the cosmetics industry for the delamination of hair.

Out Pharmacy is known that lithium compounds possess the property to be able to walk through cell membranes.

in the inventive application It can be assumed that lithium ions through the algae and fungal cell walls can migrate and therefore to the disturbance these metabolic systems and lastly destroy them.

ever higher that Lithium ion supply the faster and more intense the effect.

The long-lasting effect with lithium hydroxide-containing solutions treated surfaces can be explained by the fact that lithium hydroxide reacts with the air CO ₂ to lithium carbonate according to the equation 2LiOH + CO ₂ α Li ₂ CO ₃ + H ₂ O wherein the reaction product lithium carbonate acts as a lithium ion deposit.

In a humid atmosphere containing CO ₂ , lithium ions dissolve on a substrate in sufficient concentration to prevent reoccupation or first settlement of the surface.

When using lithium hydroxide solutions, care must be taken to avoid skin and eye contact. This can be achieved by appropriate protective measures, as in the processing of dilute alkalis and alkaline construction products, e.g. As cementitious materials are common.

Example A)

On a constructively unprotected, plastered facade of a flat roof building made of an intense Growth, consisting of strongly anchored black fungi in the substrate and so-called red algae coated up to a thickness of one millimeter, four became different lithium salt solutions applied.

The building was already 18 years old at this time.

• a) Lithiumsilikatlösung mit einem Li₂O/SiO₂-Verhältnis von 1 : 6,0 mit einer Gesamtkonzentration von 10 Masse-%
• b) Lithiumhydroxidmonohydrat, wäßrige, konzentrierte Lösung (18 Masse-% LiOH)
• c) Lithiumformiat, wäßrige Lösung (10 Masse-%)
• d) wäßrige Lithiumaluminataufschlämmung

The following lithium salt solutions were applied:

• a) Lithium silicate solution with a Li ₂ O / SiO ₂ ratio of 1: 6.0 with a total concentration of 10% by mass
• b) Lithium Hydroxide Monohydrate, Aqueous, Concentrated Solution (18% by Weight LiOH)
• c) Lithium Formate, Aqueous Solution (10% by mass)
• d) aqueous lithium aluminate slurry

It each became an area of about 15 × 10 cm with the help of a paintbrush charged and behavior on the Time watched.

Immediately after the application of the four aforementioned solutions, different color phenomena ( 1 ).
to a) color deepening ( 2 )
to b) yellowish-reddish ( 3 )
to c) dark red coloration ( 4 )
to d) lightening with whitish edge, originating from the undissolved active substance ( 5 )

To A period of three to four days showed a slow one discoloration the grayed out areas, whereby the gray to blackish ground, originating from the Fungus growth, only a brightening, but not a significant one color change learned.

From that dimmed the appearance of the surface coated with the solution according to b) was clearly off.

Because under it came the lime cement plaster with the original surface structure to the fore.

In In the following years, the same façade was weathered for ten years and the Behaved from time to time, last seen on 31.03.2004 and photographically documented.

there showed that the untreated sections meanwhile an intensive, almost related Black to reddish brown discoloration suffered interspersed with circular, plat similar Structures.

The Area, the solution a) was not repopulated, but continued to be their gray color, caused by not complete killed Fungal growth.

The erfindungegemäße solution according to b) against has prevented both a repopulation and the underground further lightened.

The Area, treated according to c) was not colonized again by algae, but by black fungus.

The Area, the one with the slurry according to d) had been colored black gray again in the meantime, d. H. repopulated by mushrooms. Picture 6 documents the just described Appearance.

Example B)

A with a lime plaster coated facade (west side) was from the ground floor to the 2nd floor and the DG almost completely covered by black microfungi and a stubborn one Red alga covered.

It was tried by means of steam jet treatment the surface of the Clean plaster and remove the vegetation.

This succeeded only moderately, d. H. Parts of the blackish Fouling had been loosened, parts of the algae were left remove.

Back stayed however, especially in the recesses of the structured plaster, a more or less intense red color, caused by the red algae growth.

To a period of three days - this one served to complete the facades allowed to dry out - was quenching the inventive solution (aqueous lithium hydroxide solution, 15%) once full enough.

there was for it Carried that the wells filled in the plaster were.

The plaster surface sucked the material of the invention intense.

In the treatment, a surface section was left untreated (upper section). There at the following phenomenon could be observed:
Immediately after the application, a color deepening of the affected facade section could be determined. After a period of about 16-20 h, the red color brightened slightly, after a period of at the latest 3 days, however, any shade of red had disappeared.

moreover No more fouling could be detected on the plaster surface.

In As a result, the facade was weathered for another year and on 31.03.04 inspected and checked.

there could be determined that the treated area was not repopulated that even the plastering surface a brightening experienced. Furthermore, it was found that the the algae and mushrooms freed facade section after weathering (Sprinkling) dried much faster than that of microorganisms populated facade section (Fig. 7).

Claims (6)

Method for controlling and preventing the growth of vegetation, in particular of algae and fungi on building surfaces, natural and natural stone surfaces, sculptures, tombstones, in particular on facades using aqueous solutions containing lithium ions, preferably lithium hydroxide solutions and mixtures with lithium hydroxide solutions, characterized in that an aqueous lithium hydroxide solution is used becomes. Method according to claim 1, characterized in that that one saturated used aqueous lithium hydroxide solution becomes. Method for fighting and to prevent the growth on buildings and sculptures, in particular of concrete, plaster and natural stone surfaces as well as surfaces which Coatings or coatings bear properties, characterized in that the treatment by spraying, Floods, diving or brushing is done. Method according to claim 3, characterized that the Treatment if necessary several times. Method of preventing the growth, by characterized in that paints and brushing lithium hydroxide in crystalline form, e.g. As lithium hydroxide, Lithium hydroxide monohydrate or added in another form. Method for preventing the growth on plasters, characterized in that already factory the dry mortar mixture Lithium hydroxide, hydrate-anhydrous, or lithium hydroxide monohydrate or added in another form becomes.