CZ36972U1 - Plaster mixture with increased resistance to biodeteriogen growth - Google Patents

Description

Current state of the art

Physical, chemical and biological influences act on the surfaces of building structures. A serious problem is biological degradation - biodeterioration, which is a change in the properties of materials caused by the activity of microorganisms, so-called deteriogens (molds, algae, lichens, mosses, microbes, yeasts, micromycetes, etc.). In addition to the aesthetic disturbance of buildings due to the growth of biodeteriogen, its effects are also biocorrosive and may also have health aspects. Biofilms or biodeteriogen retain water on the surfaces of building materials and just below it and create an environment of symbiotic coexistence of microorganisms, disrupting the compactness of these surfaces, resulting in gradual destruction. Currently, many technical solutions with biocide additives are known to increase the resistance of building materials against attack by biological agents. However, the vast majority use organic-based agents that have a limited time effectiveness with the possibility of decomposition or leaching.

Additives for plaster mixtures on an organic basis are most often used, they have a high acute effectiveness, but the prolongation of the effect cannot be expected in the case of facades that are constantly washed by rain. Even the physical effects of temperature changes (high temperatures in summer and temperatures below freezing) cause them to leak out or lyophilize (freeze) from the matrix. Last but not least, it is necessary to mention the effect of light, especially its UV component, on the decomposition of active substances on an organic basis.

An example of a classic anti-deteriogenic solution is the invention of biocorrosion-resistant concrete with the function of surface treatment, which includes the following steps: preparation of silane quaternary ammonium salt and silica fume modified with copper ions, preparation of carboxyl silane-modified nano-silica, and preparation of biocorrosion-resistant concrete using silane quaternary ammonium salt and silica fume modified copper ions as admixtures in concrete.

Also in the invention of the applicant, the owner of Rohm and Haas Company with application number US 20210017380 A1, a formulation containing an aqueous solution of a) a hydrophobically modified alkylene oxide polymer containing a hydrophobic part functionalized with a protonated secondary or protonated tertiary amine or a quaternary ammonium salt and b) an acid and its salt, which is an acid phosphoric, nitrilotris(methylene)triphosphonic, hydrochloric or sulfuric acid, while the molar ratio of the functionalized hydrophobic part to the acid and its salt is in the range from 0 to 0.5%. 3:1 to 5:1, with the proviso that if the acid is phosphoric acid, the mole ratio of the functionalized hydrophobic part to phosphoric acid and its salt is in the range of 0.8:1 to 5:1. The composition of the present invention addresses a need in the art by providing a biocide-free associative thickener that is resistant to biological damage. Hydrophobically modified ethylene oxide polymers, such as hydrophobically modified ethylene oxide urethane polymers (HEUR), are associative thickeners used to control the viscosity of waterborne coatings. HEURs supplied as aqueous solutions require a biocide, usually an isothiazolinone-based biocide such as 2-methyl-4-isothiazolin-3-one (MIT) as a preservative.

Furthermore, in the invention of the applicant, the owner of LU'AN SANCHUANG BUILDING MAT CO LTD with application number CN 107141866 A, it is based on the following raw materials in parts by weight: 5 to 12 parts of copper oxide, 3 to 6 parts of chitosan, 3 to 6 parts of algae, 6 to

- 1 CZ 36972 U1 parts 3-ethoxy-4 hydroxybenzaldehyde, 3 to 6 parts o-phenylphenol, 2 to 6 parts hydroquinone, 5 to 12 parts 8-hydroxyquinoline, 3 to 6 parts chlorothalonil, 8 to 16 parts liquid silica gel, 5 to 12 parts of soda lime and 5 to 10 parts of montmorillonite powder. The preparation method includes the following steps: preparation of powder, preparation of liquid, preparation of mixed material A, and dispersion of copper oxide, sodium lime, and montmorillonite powder to obtain a mold preventive agent.

The goal of the technical solution is to propose an additive to the standard plaster mixture, which will have antibiodeteriogenic properties with inhibition of the growth of biofilm agents of fungi, algae, bacteria without affecting the other original properties for which it was intended. It must meet all the requirements of strength or weather resistance with the use of economically advantageous materials with long-term durability and efficiency with the possibility of using even waste materials.

The essence of the technical solution

The desired goal is achieved by adding finely ground sulfur to the plaster mixture. The plaster mixture consists of mineral filler, cement, lime hydrate and additives that improve the processing and useful properties of the mortar and also contains 0.5 to 1% by weight. powdered sulfur.

Technically pure sulfur is used, commercially available, and waste sulfur from oil refining can also be used. The effect of sulfur consists in the slow release of sulfur dioxide due to atmospheric oxidation in a very low, practically unmeasurable concentration with fungicidal (antifungal) properties. It has a long-term effect, throughout the lifetime of the facade surface layer.

The resulting plaster mixture has a significantly increased resistance against the unwanted growth of biodeteriogen on the surface of the facade, retains its strength characteristics, and can use waste products.

Examples of implementing a technical solution

Example 1

Plaster mixture No. 1 was made from commercially available fine lime plaster (Fein-Kalkputz 160) with a composition of mineral filler, cement, lime hydrate and additives improving the processing and useful properties of the mortar. An increase in resistance to biodeteriogen growth was achieved by adding powdered sulfur with a quantification of 0.5 wt%. and 1.0 wt% into this plaster mix.

The plaster mix was applied using the same procedure as the original standard plaster mix according to the manufacturer's instructions.

Laboratory tests using methods within the scope of accreditation Determination of the resistance of materials against the action of algae organoleptically using ČSN EN 15458 and Determination of the resistance of materials against the action of mold organoleptically using ČSN EN 15457, ČSN 724310 and increased resistance with an accelerated aging test Modified resistance test (UV, IR , freezing) in the laboratory ATElab No. 1130.2 accredited by the Czech Institute for Accreditation according to ČSN EN ISO/IEC 17025:2018, the functionality of the given solution in increasing the resistance against the reference untreated plaster was proven.

Collection strains recommended by European standards, on which the test is based, are used for inoculation. These species occur naturally in our latitudes.

The following collection genera of fungi were used: Aspergillus niger, Penicilium brevicompactum,, Paecilomyces variotii, Alternaria alternata,, Trichoderma viride, Cladosporium cladosporioides

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The following collection genera of algae were used: Nostoc commune, Stichococcus bacillaris

Exposure of resistance to algae takes place at a temperature of 25 ± 2 °C, relative humidity unregulated, i.e. approx. 50%

Exposure to mold resistance takes place at a temperature of 25 ± 2 °C, relative humidity of 95 ± 5%

A negative control means - confirmation of the unequivocal action of the disinfectant

Positive control means - confirmation of the viability of the inoculum of the test organism

Mold resistance results

0.5% powdered sulfur was homogeneously added to mixture #1

The plaster mix is applied using the same procedure as the original standard plaster mix.

Sample Sulfur admixture Years of exposure Average coverage of the sample area by mold growth mixture #1 0.0% control negative 0 0% mixture #1 0.0% control positive 0 100% mixture #1 0.5% 3 30% mixture #1 0.5% 5 50% mixture #1 0.5% 7 50% mixture #1 0.5% 10 60%

1.0% powdered sulfur was homogeneously added to mixture #1

The plaster mix is applied using the same procedure as the original standard plaster mix.

Sample Sulfur admixture Years of exposure Average coverage of the sample area by mold growth mixture #1 0.0% control negative 0 0% mixture #1 0.0% control positive 0 100% mixture #1 1.0% 3 15% mixture #1 1.0% 5 20% mixture #1 1.0% 7 20% mixture #1 1.0% 10 30%

CZ 36972 UI

Algae resistance results

0.5% powdered sulfur was homogeneously added to mixture #1

The plaster mix is applied using the same procedure as the original standard plaster mix.

sample Sulfur admixture Years of exposure Average coverage of the sample area by algal growth mixture #1 0.0% control negative 0 0% mixture #1 0.0% control positive 0 100% mixture #1 0.5% 3 20% mixture #1 0.5% 5 30% mixture #1 0.5% 7 50% mixture #1 0.5% 10 60%

% powdered sulfur was homogeneously added to mixture #1

The plaster mix is applied using the same procedure as the original standard plaster mix

Sample Sulfur admixture Years of exposure Average coverage of the sample area by algal growth mixture #1 0.0% control negative 0 0% mixture #1 0.0% control positive 0 100% mixture #1 1.0% 3 5% mixture #1 1.0% 5 10% mixture #1 1.0% 7 20% mixture #1 1.0% 10 45%

Example 2

Plaster mixture No. 2 was produced from a commercially available plaster mixture (Cemix Universal masonry and plaster mixture) with a composition of mineral filler, cement, lime hydrate and additives that improve the processing and useful properties of the mortar. An increase in resistance to biodeteriogen growth was achieved by adding powdered sulfur with a quantification of 0.5 wt%. and 1.0 wt% into this plaster mix.

The plaster mix was applied using the same procedure as the original standard plaster mix according to the manufacturer's instructions.

Laboratory tests using methods within the scope of accreditation Determination of the resistance of materials against the action of algae organoleptically using CSNEN 15458 and Determination of the resistance of materials against the action of mold organoleptically using ČSN EN 15457, ČSN 724310 and increased resistance with an accelerated aging test Modified resistance test (UV, IR , freezing) in the ATElab laboratory No. 1130.2 accredited by the Czech Institute for Accreditation according to ČSN EN ISO/IEC 17025:2018, the functionality of the given solution in increasing the resistance against reference 30 untreated plaster was proven.

Collection strains recommended by European standards, on which the test is based, are used for inoculation. These species occur naturally in our latitudes.

The following collection genera of fungi were used: Aspergillus niger, Penicilium brevicompactum, Paecilomyces variotii, Alternaria altemata,, Trichoderma viride, Cladosporium cladosporioides

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The following collection genera of algae were used: Nostoc commune, Stichococcus bacillaris

Exposure of resistance to algae takes place at a temperature of 25 ± 2 °C, relative humidity unregulated Ij approx. 50%

Exposure to mold resistance takes place at a temperature of 25 ± 2 °C, relative humidity of 95 ± 5%

A negative control means - confirmation of the unequivocal action of the disinfectant

Positive control means - confirmation of the viability of the inoculum of the test organism

Mold resistance results

0.5% of powdered sulfur was homogeneously added to mixture No. 2

The plaster mix is applied using the same procedure as the original standard plaster mix.

Sample Sulfur admixture Years of exposure Average coverage of the sample area by mold growth mixture no. 2 0.0% control negative 0 0% mixture no. 2 0.0% control positive 0 100% mixture no. 2 0.5% 3 35% mixture no. 2 0.5% 5 45% mixture no. 2 0.5% 7 50% mixture no. 2 0.5% 10 60%

1.0% of powdered sulfur was homogeneously added to mixture No. 2

The plaster mix is applied using the same procedure as the original standard plaster mix.

Sample Sulfur admixture Years of exposure Average coverage of the sample area by mold growth mixture no. 2 0.0% control negative 0 0% mixture no. 2 0.0% control positive 0 100% mixture no. 2 1.0% 3 10% mixture no. 2 1.0% 5 20% mixture no. 2 1.0% 7 25% mixture no. 2 1.0% 10 35%

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Algae resistance results

0.5% of powdered sulfur was homogeneously added to mixture No. 2

The plaster mix is applied using the same procedure as the original standard plaster mix.

Sample Sulfur admixture Years of exposure Average coverage of the sample area by algal growth mixture no. 2 0.0% control negative 0 0% mixture no. 2 0.0% control positive 0 100% mixture no. 2 0.5% 3 25% mixture no. 2 0.5% 5 30% mixture no. 2 0.5% 7 55% mixture no. 2 0.5% 10 60%

% of powdered sulfur was homogeneously added to mixture No. 2

The plaster mix is applied using the same procedure as the original standard plaster mix

Sample Sulfur admixture Years of exposure Average coverage of the sample area by algal growth mixture no. 2 0.0% control negative 0 0% mixture no. 2 0.0% control positive 0 100% mixture no. 2 1.0% 3 5% mixture no. 2 1.0% 5 15% mixture no. 2 1.0% 7 25% mixture no. 2 1.0% 10 45%

The universality of use was demonstrated by the use of 2 standard, common plaster mixes, with similar test results. The technological properties of the plaster mixtures did not change with the addition.

Claims (1)

PROTECTION CLAIMS 1. Plaster mixture with increased resistance against the growth of biodeteriogen, consisting of mineral filler, cement, lime hydrate and additives improving the processing and useful properties of the mortar, 5 characterized by the fact that it also contains 0.5 to 1 wt.%. powdered sulfur.