Aqueous industrial product stabilized against microbial contamination

Abstract

The invention relates to an aqueous industrial product selected from the group consisting of a paint, a plaster / render, a varnish, a stain, a polymer emulsion, a slurry and a pigment preparation, which contains (a) 0.03% to 1.4% by weight of guanidine and / or at least one salt of guanidine, the proportion by weight being based on the content of guanidine in the entire aqueous product, and which is characterized in that it has a pH in the range from pH 7.5 to 12.0. The invention further relates to a method for stabilizing an aqueous industrial product against microbial contamination, comprising the method steps of: (a) providing an aqueous industrial product, (b) mixing 0.03% to 1.4% by weight of at least one salt of guanidine with the aqueous industrial product, and (c) optionally adjusting the pH so that the stabilized aqueous industrial product has a pH in the range from pH 7.5 to 12.0. The present invention further relates to a method for producing an aqueous industrial product.

Description

[0001] Aqueous technical product stabilized against microbial attack

[0002] The invention relates to an aqueous technical product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation, which contains (a) 0.03 to 1.4 wt. % guanidine and / or at least one salt of guanidine, where the weight fraction relates to the content of guanidine in the entire aqueous product, and which is characterized in that it has a pH in the range from pH 7.5 to 12.0. The invention further relates to a process for stabilizing an aqueous technical product against microbial attack, which process comprises the steps of: (a) providing an aqueous technical product, (b) mixing 0.03 to 1.4 wt.- % of at least one salt of guanidine with the aqueous technical product, and (c) optionally adjusting the pH so that the stabilized aqueous technical product has a pH in the range of pH 7.5 to 12.0. The present invention further relates to a process for producing an aqueous technical product.

[0003] Technical products, especially water-based ones, such as paints, varnishes, glazes, plasters, and emulsions, are typically manufactured using natural or biodegradable raw materials. These raw materials and the water used as a solvent are often contaminated with germs such as bacteria, yeasts, and fungi. If these products are not preserved during production, they can exhibit high bacterial counts just one day after production.

[0004] To ensure that these products, and possibly also the components used in their manufacture, meet hygiene requirements and to guarantee the durability of the technical products, so-called biocides are usually added to the products or even to their components. One class of biocides used to preserve aqueous coatings such as paints, plasters, varnishes, or glazes, or components thereof, is the so-called 3-isothiazolin-3-ones. This class of substances contains highly antimicrobially effective compounds, some of which have different activity profiles. Synergistic combinations of different 3-isothiazolin-3-ones are often used to reduce the amount of biocide used. For example, WO 99 / 08530 A1 proposes the combined use of methylisothiazolin-3-one and 1,2-benzisothiazolin-3-one.

[0005] Another class of biocides are the so-called alkylguanidinium salts and polyguanidinium salts. For example, it is known from the "Directory of Microbicides for the Protection of Materials," Springer 2005, pages 726 to 731, that medium- and long-chain guanidines and biguanidines, such as cocospropylenediamine-1,5-bis-guanidinium acetate, bis(guanidinooctyl)amine triacetate, poly(hexamethylenebiguanidine) hydrochloride, di(4'-chlorophenyldiguanido)hexane, chlorhexidine digluconate, and chlorhexidine diacetate, exhibit antimicrobial activity.

[0006] Furthermore, the use of such medium- and long-chain guanidine compounds in combination with other antimicrobial and / or fungicidal agents is known. For example, the combination with 3-iodo-2-propynyl butylcarbamate or formaldehyde depot substances is known. For example, EP 0 891 710 A1 teaches the combined use of dodecylguanidine hydrochloride and IPBC. However, the use of dodecylguanidine salts for the preservation of paint compositions and polymer dispersions has proven problematic, with incompatibilities in the form of coagulation observed upon addition of these salts.

[0007] Sometimes the use of conventional biocides or preservatives is not even considered because they are increasingly subject to legal restrictions.

[0008] It has therefore already been proposed to create storage-stable aqueous coating materials of the type considered here without conventional preservatives by raising their pH to such an extent that microbial attack is effectively prevented. The goal is a pH of at least 10, since microbial attack cannot be prevented with sufficient reliability at lower pH values.

[0009] In the prior art, the pH value is increased by adding water glass, for example according to EP 1 297 079 A1.

[0010] Alternatively, DElO 2014 013 455 A1 and WO2017 / 144694 A1 disclose the use of siliconates as pH-increasing additives.

[0011] A disadvantage of the above-described preservation methods, however, is the comparatively high pH values ​​in the coating materials required for preservation, which requires particular care in their handling. Furthermore, these coating materials have recently been increasingly exposed to contamination by alkaliphilic germs, microorganisms that can survive and multiply under alkaline conditions.

[0012] Despite the numerous known active ingredient combinations and measures taken in the meantime, there is an increased demand, particularly due to increasing regulatory restrictions, for products stabilized against microbial contamination, which preferably do not contain or contain a reduced content of classic preservatives or biocides, such as isothiazolinones, bronopol and pyrithiones.

[0013] This object is achieved by an aqueous technical product which is stabilized against microbial attack and is selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation, containing:

[0014] (a) 0.03 to 1.4 wt.%, preferably 0.07 to 1.2 wt.%, particularly preferably 0.1 to

[0015] 1.0% by weight of guanidine and / or at least one salt of guanidine, wherein the weight fraction refers to the guanidine content in the entire aqueous product, characterized in that the technical product has a pH in the range from 7.5 to 12.0, preferably from pH 8 to 11.5, particularly preferably from pH 8.5 to 11. Due to their composition, the aqueous technical products stabilized against microbial attack according to the invention require significantly fewer, and in some cases even no, preservatives, such as are usually contained in such products for in-container preservation. Nevertheless, these products are characterized by excellent resistance to microbial attack, particularly during storage, due to the surprisingly effective interaction of the guanidine or the guanidine salt and the corresponding pH in the range from pH 7.5 to 12.0.As a result, the aforementioned technical products are significantly improved in terms of their environmental compatibility and also exhibit all known properties related to good and safe processing. Furthermore, the products according to the invention are particularly protected against attack by adapted alkaliphilic microorganisms, in particular against alkaliphilic bacteria and against neutrophilic to less alkaliphilic bacteria. This allows them to be formulated with a less strongly alkaline content, which is advantageous with regard to safe processing.

[0016] According to a preferred embodiment of the invention, the aqueous technical product is substantially free, preferably completely free, of preservatives selected from the group consisting of 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, l,2-benzisothiazolin-3-one, N-butyl-l,2-benzisothiazolin-3-one, N-methyl-l,2-benzisothiazolin-3-one, octylisothiazolinone, dichlorooctylisothiazolinone, dithiobisbenzmethylamide, formaldehyde and formaldehyde releasers, quaternary ammonium compounds, bronopol, dibromonitrilopropionamide, dibromodicyanobutane, iodopropynyl butylcarbamate, thiabendazole, sodium pyrithione, zinc pyrithione, o-phenylphenol and combinations thereof.

[0017] Essentially free in this context means that the technical product contains a total amount of less than 10 ppm, preferably less than 5 ppm, particularly preferably less than 1 ppm, based on the entire product.

[0018] Aqueous technical product in the sense of the present invention generally means a water-containing technical product which is selected from the group consisting of a paint, such as an interior paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation, which has component (a) and a pH within the claimed range.

[0019] The aqueous technical product according to the present invention is the technical products listed below:

[0020] Coating materials such as paints, varnishes, plasters, lacquers and glazes,

[0021] Polymer dispersions based on polyacrylate, polystyrene acrylate, styrene butadiene or polyvinyl acetate,

[0022] Pigment preparations, coloring and tinting pastes and

[0023] Slurries or pastes of raw materials such as inorganic or organic color pigments, such as iron oxide pigments and carbon black pigments, or slurries or pastes of inorganic or synthetic fillers and pigments, such as kaolin, calcium carbonate, calcium silicate hydrate, calcium aluminate sulfate, titanium dioxide, gypsum, bentonite, magnesium silicates, smectide or talc.

[0024] The aqueous technical product according to the invention is particularly preferably a paint, a plaster, a varnish, or a glaze. The paint can be a paint for indoor or outdoor use. The plaster can also be a plaster for outdoor use as well as for indoor use. Likewise, the plaster can be a sealant or filler for outdoor use as well as for indoor use.

[0025] In the context of the present invention, the data "wt%" refer to the entire aqueous technical product.

[0026] In the context of the invention, at least one salt of guanidine means that the aqueous technical product contains one or two, three, four, five or six, i.e. also a mixture of salts of guanidine.

[0027] The aqueous technical product according to the invention contains, as component (a), guanidine and / or at least one guanidine salt in an amount ranging from 0.03 to 1.4% by weight, where the stated weight fraction relates to the guanidine content in the entire technical product, so that stabilization against microbial attack occurs, particularly during storage. The amount of component (a) required for stabilization is determined by the person skilled in the art depending on the particular product using methods familiar to them. The aqueous technical products stabilized against microbial attack exhibit improved stability against attack by microorganisms compared to unstabilized aqueous technical products, i.e. products that contain no guanidine or no guanidine salt, or that contain too small an amount of guanidine or its salt, and are therefore less prone to contamination.Within the scope of the invention, it has been found that guanidine amounts of up to 1.5 wt.%, preferably up to 1.2 wt.%, and particularly preferably up to 1 wt.% are sufficient to ensure stabilization of the product against attack by microorganisms. Higher amounts than, for example, 1.4 wt.% guanidine are undesirable from a practical perspective, with regard to stabilization, and especially from an economic perspective.

[0028] The aqueous technical product is characterized in that component (a) is present in the aqueous technical product in a range of 0.03 to 1.4 wt.%, preferably in the range of 0.07 to 1.2 wt.%, particularly preferably in the range of 0.1 to 1.0 wt.%, wherein the stated weight fraction refers to the content of unsubstituted guanidine according to the formula shown below: in the entire aqueous technical product. Therefore, when determining the guanidine content, in the case of the presence of guanidine salts, only the guanidine content is taken into account, without taking into account any counterion.

[0029] The guanidine salt that may be present in the aqueous technical product is preferably at least one guanidine salt selected from the group consisting of guanidine hydrochloride, guanidine carbonate, guanidine nitrate, guanidine sulfate, guanidine thiocyanate, guanidine phosphate, guanidine hydrogen carbonate, guanidine formate, guanidine acetate, guanidine silicate, and / or guanidine citrate. At least one guanidine salt means that one, two, three, four, five, or more guanidine salts may be present.

[0030] The salts of guanidine within the meaning of the present invention are non-substituted guanidine or guanidinium salts of the general formula shown below: where n is 1, 2 or 3, and where the counterion X n ' for example chloride, carbonate, nitrate, sulfate, thiocyanate, phosphate, bicarbonate, formate, acetate or citrate.

[0031] According to a preferred embodiment of the invention, the aqueous technical product contains as component (a) guanidine hydrochloride and / or guanidine carbonate, according to a particularly preferred embodiment of the invention, the aqueous technical product contains as component (a) guanidine carbonate.

[0032] The pH of the aqueous technical product generally ranges from pH 7.5 to 12. According to a preferred embodiment of the invention, the aqueous technical product is characterized by having a pH in the range from 8 to 11.5, preferably a pH in the range from 8.5 to 11. By adjusting the pH to a value in the range from 8.5 to 11, more skin-compatible technical products, such as coating compositions, and thus products with additionally improved properties are obtained. Thus, fewer requirements need to be observed, particularly with regard to the handling of the products according to the invention.

[0033] The pH can be adjusted to the claimed range using methods familiar to those skilled in the art. This can be achieved, for example, by using guanidine carbonate as the guanidine salt. The pH can also be adjusted to the claimed range by adding alkaline substances, also known as alkali adjusters. Such compounds for adjusting the pH are known to those skilled in the art; the respective amounts used can vary over a wide range, which the skilled person can determine using methods familiar to them. Examples of alkali adjusters are:

[0034] • Guanidine carbonate,

[0035] • Alkali metal hydroxides such as lithium, sodium and / or potassium hydroxide,

[0036] • Alkaline earth metal hydroxides such as magnesium, calcium and / or barium hydroxide, ammonium hydroxide, xonotlite and / or ettringite (Ca6[Al(OH)ö]2(SO4 x 26 H2O)),

[0037] • Water glass such as sodium, lithium and potassium water glass, or mixtures of these,

[0038] • Siliconates, such as alkali metal alkyl siliconates or alkaline earth alkyl siliconates, in particular compounds according to the general formula R-Si(OH)2OM A or [R-Si(OH)2O]2M E where M A for an alkali metal such as lithium, sodium, potassium, M E represents an alkaline earth metal such as magnesium or calcium and R represents an alkyl radical such as methyl, ethyl, n-propyl, i-propyl, n-butyl or i-butyl,

[0039] • Buffer systems, for example based on at least one phosphate or polyphosphate salt, preferably K3PO4 or Na3PO4, and at least one alkali hydroxide, preferably lithium, sodium and / or potassium hydroxide,

[0040] • Alkali and / or alkaline earth carbonates and / or hydrogen carbonates,

[0041] • Ammonia and ammonium compounds,

[0042] • Amines, amino compounds and amino alcohols.

[0043] According to a preferred embodiment of the invention, the pH value is adjusted to the required range using guanidine carbonate.

[0044] In the context of the present invention, an aqueous technical product means that the product has a water content, which makes it somewhat susceptible to microbial attack. In the context of the present invention, an aqueous technical product means a product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry, and a pigment preparation, in particular a water-based paint, a varnish, a glaze, or a plaster with a water content of at least 10% by weight, preferably at least 15% by weight, particularly preferably at least 20% by weight. The paint can be a paint for interior use or a paint for exterior use. The plaster can also be a plaster for exterior use as well as for interior use. Likewise, in the context of the present invention, the plaster can be a filler for exterior use as well as for interior use.As already described in the introduction, such aqueous technical products are typically manufactured using natural or biodegradable raw materials. These raw materials and the water used as a solvent are often contaminated with microorganisms such as bacteria, yeasts, and fungi. The water content in the aqueous technical product can vary widely and is preferably in the range of 10 to 90 wt.%, based on the total aqueous technical product.

[0045] As already described in the introduction to the description, it has already been proposed to provide storage-stable aqueous coating materials, such as paints and plasters, of the type considered here with a low content, preferably without, of conventional preservatives by increasing their pH to such an extent that microbial attack is effectively prevented. The goal is a pH of at least 10. Thus, in the prior art, the pH is increased by adding water glass, for example, according to EP 1 297 079 A1. Alternatively, DE10 2014 013 455 A1 and WO2017 / 144694A1 disclose the use of siliconates as a pH-increasing additive.

[0046] A disadvantage of these approaches, however, is the necessary high pH values ​​in the coating materials, which requires particular care in their handling. In addition, infestation by alkaliphilic germs has recently been observed in these coating materials. There was therefore a need for products with improved stabilization against microbial attack, such as paints and plasters, which manage with a low content of conventional preservatives, preferably without conventional preservatives or biocides, such as isothiazolinones, pyrithiones and formaldehyde. This further object is achieved by an aqueous technical product stabilized against microbial attack, which is selected from a paint and a plaster, comprising: (a) 0.03 to 1.4 wt. %, preferably 0.07 to 1.2 wt. %, particularly preferably 0.1 to

[0047] 1.0% by weight of guanidine and / or at least one salt of guanidine, the weight proportion being based on the content of guanidine in the total aqueous technical product,

[0048] (b) 1.0 to 85 wt.% pigment and / or filler, (c) 1 to 30 wt.% polymer dispersion calculated as solids content and

[0049] (d) 100% supplemented proportions of water, characterized in that the technical product has a pH in the range from pH 7.5 to 12.0, preferably in the range from pH 8.5 to pH 11.5, or is adjusted to a pH in the range from pH 7.5 to 12.0, preferably in the range from pH 8.5 to pH 11.5.

[0050] Surprisingly, it has been found in connection with this embodiment of the present invention that the presence of guanidine or its salt in the aqueous technical product, which is a paint or plaster and which has a pH in the range from pH 7.5 to 12.0, preferably in the range from pH 8.5 to 11.5, results in a product that is significantly less susceptible to microbial attack than those known from the prior art. Due to their composition, the paints and plasters according to this embodiment require significantly less preservatives in the form of so-called biocides, as are usually contained in coating materials such as emulsion paints and plasters for container preservation, and yet still have excellent storage stability. For outdoor use, the paint or plaster can be...However, if necessary, additional biocidal substances such as algicides and fungicides can be added to the plaster to protect the film.

[0051] According to this preferred embodiment of the invention, the technical product, which is a paint or a plaster, is substantially free, preferably completely free, of preservatives selected from the group consisting of 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, l,2-benzisothiazolin-3-one, N-butyl-1,2-benzisothiazolin-3-one, N-methyl-l,2-benzisothiazolin-3-one, octylisothiazolinone, Diehl oroctylisothiazolinone, dithiobisbenzmethylamide, formaldehyde and

[0052] Formaldehyde breakers, quaternary ammonium compounds, bronopol, dibromonitrilopropionamide, dibromodicyanobutane, iodopropynyl butylcarbamate, thiabendazole, sodium pyrithione, zinc pyrithione, o-phenylphenol and combinations thereof.

[0053] Essentially free in this context means that the aqueous technical product contains a total amount of less than 10 ppm, preferably less than 5 ppm, particularly preferably less than 1 ppm, based on the aqueous technical product.

[0054] The guanidine salt that may be present in the aqueous technical product, such as a paint or plaster, is generally at least one guanidine salt selected from the group consisting of guanidine hydrochloride, guanidine carbonate, guanidine nitrate, guanidine sulfate, guanidine thiocyanate, guanidine phosphate, guanidine hydrogen carbonate, guanidine formate, guanidine acetate, and / or guanidine citrate. At least one guanidine salt means that one, two, three, four, five, or more guanidine salts may be present.

[0055] According to a preferred embodiment of the invention, the aqueous technical product, which is a paint or a plaster, contains as component (a) guanidine hydrochloride and / or guanidine carbonate; according to a particularly preferred embodiment of the invention, the aqueous technical product contains as component (a) guanidine carbonate.

[0056] The pH of the aqueous technical product according to this embodiment is generally in a range from pH 7.5 to 12. According to a preferred embodiment of the invention, the aqueous technical product is characterized in that it has a pH in the range from pH 8.5 to 11.5. By adjusting the pH to a value in the range from pH 8.5 to 11.5, more skin-compatible paints or plasters, and thus products with additionally improved properties, are obtained, which is particularly advantageous with regard to their safe processing. The aqueous technical product, which is a paint or plaster, generally contains 1.0 to 85% by weight of pigment and / or filler as component (b). According to a preferred embodiment of the invention, the coating composition contains 1 to 25% by weight of pigments and / or 5 to 50% by weight of fillers.

[0057] The usual pigment admixtures of emulsion paints can be used as pigments, such as titanium dioxide, iron oxide, chromium oxide, cobalt blue, phthalocyanine pigments, spinel pigments as well as nickel and chromium titanates.

[0058] Silicates, carbonates, fluorspar, sulfates and oxides are preferably included as fillers in the composition.

[0059] As component (c), the aqueous technical product, which is a paint or plaster, generally contains 1 to 30 wt. %, preferably 2 to 20 wt. %, particularly preferably 3 to 12 wt. % polymer dispersion, calculated in each case as the solids content of the polymer dispersion. The polymer dispersions contained in the coating composition can be any polymer dispersions known per se from the prior art in the field of coating or paint systems. The properties of the dispersion, as well as of the finished products produced from it, are predominantly determined by the respective polymer. The polymer is composed of various building blocks, the so-called monomers, which can also be combined with one another depending on the desired property profile.Suitable monomers include, for example, vinyl carboxylates having 3 to 20 carbon atoms, N-vinylpyrrolidone, vinyl aromatics, vinyl halides, ethylenically unsaturated carboxylic acids, their esters, their amides, or their anhydrides, nanohybrid dispersions, waterglass, silicone resin emulsions, aqueous polyurethane dispersions, styrene acrylates, α-olefins, and / or 1,3-dienes in the form of aqueous polymer dispersions or water-redispersible polymer powders. Particular preference is given to the use of ethylenically unsaturated carboxylic acids, in particular acrylic and methacrylic acid, and also ethylenically unsaturated carboxylic acid esters, in particular acrylic and methacrylic acid esters having 1 to 12 carbon atoms in the alcohol moiety. The alcohol residue of the esters can consist of linear or branched alkyl chains, cycloaliphatics or aromatics, which can additionally be modified with hydroxyl groups, halogen atoms or epoxy groups.The use of styrene and styrene derivatives is also particularly preferred.

[0060] As component (d), the aqueous technical product, which is a paint or plaster, contains 100% added water. The water content can generally vary over a wide range and is at least 10% by weight, preferably at least 15% by weight, particularly preferably at least 20% by weight.

[0061] Furthermore, the aqueous technical product, which is a paint or plaster, may contain additional additives such as dispersants, thickeners, stabilizers, defoamers and / or hydrophobic agents.

[0062] The invention also relates to the use of the aqueous technical products according to the invention, which are paints or plasters, for indoor and outdoor use. It has been found that these are particularly suitable for indoor use due to the absence of conventional in-can preservatives.

[0063] This invention further relates to a process for producing the aqueous technical products according to the invention, comprising mixing the components defined above.

[0064] The present invention further relates to a process for stabilising an aqueous technical product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation against microbial attack, which process comprises the following steps:

[0065] (a) Providing an aqueous technical product,

[0066] (b) mixing at least one salt of guanidine with the technical product and

[0067] (c) optionally adjusting the pH, characterized in that the stabilized aqueous technical product has a pH in the range from pH 7.5 to 12.0, preferably from pH 8 to 11.5, particularly preferably from pH 8.5 to 11, and further characterized in that the amount of the guanidine salt or guanidine salts is in the range from 0.03 to 1.4 wt.%, preferably in the range from 0.07 to 1.2 wt.%, particularly preferably in the range from 0.1 to 1.0 wt.%, wherein the weight fraction relates to the content of guanidine in the entire aqueous technical product.

[0068] The process according to the invention is advantageously characterized in that it can be used to produce aqueous technical products stabilized against microbial attack, which, due to their composition, require significantly fewer, in some cases even no, preservatives, such as those typically contained in aqueous technical products, such as emulsion paints, for container preservation. Nevertheless, due to the surprisingly effective interaction of the at least one guanidine salt or the resulting guanidine and the corresponding pH value in the range of pH 7.5 to 12.0, the aqueous technical products are characterized by excellent resistance to microbial attack, particularly during storage. This significantly improves the products' environmental compatibility.

[0069] In step (a) of the process according to the invention, the aqueous technical product to be stabilized against microbial attack, which is selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry, and a pigment preparation, is provided. Stabilizing against microbial attack, in the context of the present invention, means that, in an unstabilized state, it is prone to microbial attack, particularly during storage, and thus deteriorates.

[0070] The aqueous technical product provided in step (a) is mixed with at least one guanidine salt in process step (b). The amount of guanidine salt required for stabilization is determined by the person skilled in the art depending on the particular product using methods familiar to them. The aqueous technical products stabilized against microbial attack have improved stability against attack by microorganisms compared to non-stabilized aqueous technical products, i.e. products which contain no salt of guanidine or guanidine or which contain too small an amount of the guanidine salt or guanidine, and are therefore less prone to contamination. The amount of guanidine salt or guanidine salts used in process step (b) can vary across ranges depending on the technical product provided and is in the range from 0.03 to 1.4% by weight, preferably in the range from 0.07 to 1.2% by weight.-%, particularly preferably in the range from 0.1 to 1.0 wt.%, wherein the weight fraction refers to the content of guanidine, without taking into account any counterion, in the entire aqueous technical product.

[0071] According to a preferred embodiment of the invention, guanidine hydrochloride and / or guanidine carbonate is used in process step (b), and according to a particularly preferred embodiment of the invention, guanidine carbonate is used.

[0072] In process step (c) of the process for stabilizing the aqueous technical product, the pH is optionally adjusted so that the aqueous technical product has a pH in the range from pH 7.5 to 12.0, preferably in the range from pH 8 to 11.5, particularly preferably in the range from pH 8.5 to 11. Optionally means that the pH is already in the range from pH 7.5 to 12.0, preferably in the range from pH 8 to 11.5, particularly preferably in the range from pH 8.5 to 11, due to the composition of the product or due to the guanidine salt used after process step (b), so that adjustment is not necessary.

[0073] The present invention further relates to a process for producing an aqueous technical product stabilized against microbial attack, selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation, which comprises the process steps:

[0074] (a) Providing an aqueous technical product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation,

[0075] (b) mixing at least one salt of guanidine with the aqueous technical product such that the amount of guanidine salt, based on the content of guanidine in the total aqueous technical product, is in the range from 0.03 to 1.4% by weight and

[0076] (c) optionally adjusting the pH, characterized in that the aqueous technical product produced has a pH in the range from pH 7.5 to 12.0, preferably in the range from pH 8 to 11.5, particularly preferably in the range from pH 8.5 to 11.

[0077] The manufacturing process according to the invention is advantageously characterized by the fact that it can be used to produce aqueous technical products stabilized against microbial attack, which, due to their composition, require significantly fewer, and in some cases even none at all, preservatives, such as those typically contained in these products for in-container preservation. Nevertheless, due to the surprisingly effective interaction of the at least one guanidine salt and the corresponding pH value in the range of pH 7.5 to 12.0, the technical products are characterized by excellent resistance to microbial attack, particularly during storage.

[0078] In step (a) of the manufacturing process according to the invention, the aqueous technical product to be stabilized against microbial attack, selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry, and a pigment preparation, is prepared. Stabilizing against microbial attack, in the context of the present invention, means that, in an unstabilized state, the product is prone to microbial attack, particularly during storage, and thus deteriorates.

[0079] The aqueous, technical product prepared in step (a) is mixed with at least one guanidine salt in process step (b). The amount of guanidine salt required for stabilization is determined by the skilled person, depending on the particular product provided, using methods familiar to them. Products stabilized against microbial attack exhibit improved stability against attack by microorganisms compared to non-stabilized compositions—i.e., compositions that contain no salt of unsubstituted guanidine or contain too small a quantity of the guanidine salt—and are therefore less prone to contamination.

[0080] The amount of guanidine salt(s) used in process step (b) can vary over a wide range depending on the product provided and is in the range from 0.03 to 1.4 wt.%, preferably in the range from 0.07 to 1.2 wt.%, particularly preferably in the range from 0.1 to 1.0 wt.%, wherein the weight fraction relates to the content of guanidine, without taking into account any counterions, in the entire aqueous technical product.

[0081] According to a preferred embodiment of the invention, guanidine hydrochloride and / or guanidine carbonate is used in process step (b), and according to a particularly preferred embodiment of the invention, guanidine carbonate is used.

[0082] In process step (c) of the process for producing the aqueous technical product, the pH is optionally adjusted so that the product produced has a pH in the range from pH 7.5 to 12.0, preferably in the range from pH 8 to 11.5, particularly preferably in the range from pH 8.5 to 11. Optionally means that the pH is already in the range from pH 7.5 to 12.0, preferably in the range from pH 8 to 11.5, particularly preferably in the range from pH 8.5 to 11, due to the composition of the product or due to the guanidine salt used after process step (b), so that adjustment is not necessary.

[0083] The invention further relates to the use of guanidine and / or at least one salt of guanidine in an aqueous technical product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation, which has a pH in the range from pH 7.5 to 12.0, preferably in the range from pH 8 to 11.5, particularly preferably in the range from pH 8.5 to 11, in an amount in the range from 0.033 to 2.0 wt.%, preferably in the range from 0.07 to 1.7 wt.%, particularly preferably in the range from 0.1 to 1.4 wt.%, where the weight fraction relates to the content of guanidine, without taking into account any counterion, in the entire aqueous product, for stabilizing the aqueous product against microbial attack. Advantageously, the use of the guanidine orof the at least one guanidine salt in the aqueous technical product as defined above, the elimination of conventional preservatives, such as those typically contained in such products for in-container preservation. This significantly improves the products' environmental compatibility. The claimed aqueous technical products also exhibit all known properties related to good and safe processing properties. Furthermore, the products according to the invention are particularly protected against attack by adapted alkaliphilic microorganisms as well as against neutrophilic to less alkaliphilic microorganisms.

[0084] According to a preferred embodiment, the present invention relates to an aqueous technical product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation, containing:

[0085] (a) 0.03 to 1.4% by weight, preferably 0.07 to 1.2% by weight, particularly preferably 0.1 to 1.0% by weight of guanidine and / or at least one salt of guanidine, wherein the weight fraction relates to the content of guanidine in the total aqueous technical product,

[0086] (b) 0.001 to 0.01 wt.%, preferably 0.001 to 0.005 wt.% of 5-chloro-2-methylisothiazolin-3-one (CMIT) and

[0087] (c) 100% supplemented with water, characterized in that the aqueous technical product has a pH in the range of pH 9.0 to 11.0 or is adjusted to a pH in the range of pH 9.0 to 11.

[0088] The advantages of this embodiment of the invention are that, on the one hand, 5-chloro-2-methylisothiazolin-3-one is contained in the technical product as a so-called quick-kill biocide, and causes rapid and effective destruction of the germs contained in the coating agent. This effectively and quickly inactivates microorganisms present during production, such as bacteria, yeasts, and fungi. Furthermore, the alkaline pH of the aqueous technical product leads to a gradual degradation of the 5-chloro-2-methyl-4-isothiazolone, so that after just a few days, it is present only in comparatively low concentrations, if at all. Thus, the products can be considered largely unproblematic for the end user.Since the aqueous technical product, which has a pH value in the range of pH 9 to pH 11, also contains at least one guanidine salt, the product is also effectively stabilized against possible subsequent contamination during transport and storage. According to a preferred embodiment of the invention, the aqueous technical product is characterized in that the 5-chloro-2-methyl-4-isothiazolone (CMIT) has a 2-methyl-4-isothiazolin-3-one content in the range of 0 to 2 wt. %, based on the total content of 5-chloro-2-methyl-4-isothiazolin-3-one.

[0089] This embodiment of the invention advantageously makes it possible to obtain products stabilized against microbial attack using the highly effective 5-chloro-2-methyl-4-isothiazolin-3-one, which, after their production and storage, are particularly suitable for persons with a high degree of sensitization to 5-chloro-2-methylisothiazolin-3-one or 2-methylisothiazolin-3-one.

[0090] The following examples serve to further illustrate the present invention:

[0091] To demonstrate the stabilization of the claimed aqueous technical products against microbial attack through the surprising interaction between the alkaline pH range and the guanidinium ions, various emulsion paints with different pH values ​​as well as a calcium carbonate slurry containing different amounts of guanidine salts were added and tested for their stability against microbial attack:

[0092] The colors and their components tested were as follows:

[0093] Colour 1 : Dispersion paint (PVK 77%) for interior use with a pH value of

[0094] 7,8, produced in the laboratory on the basis of vinyl acetate-ethylene binder, without the addition of the otherwise conventional preservatives.

[0095] Paint 2: Dispersion paint (PVK 77%) for interior use with a pH value of

[0096] 8.4, produced in the laboratory on the basis of styrene acrylate, without the addition of the otherwise usual conventional preservatives.

[0097] Color 3: Commercially available, so-called preservative-free alkaline

[0098] Dispersion paint for interior use with a pH value of 11.3 (Alpina White The Original, free from solvents and preservatives)

[0099] Calcium carbonate slurry: Calcium carbonate slurry, free from preservatives with a solids content of 78% and a pH of 9.2.

[0100] Procedure:

[0101] Colors 1 to 3 were mixed with different concentrations of the guanidinium salts to be tested and homogenized.

[0102] The resulting batches of the prepared paint were inoculated several times with a mixture of various wild-type bacterial strains relevant to contamination in practice. These bacteria had previously been isolated from commercial emulsion paints containing conventional preservatives and microbially contaminated in practice (bacterial mixture 1, genus Pseudomonas), as well as from commercial preservative-free alkaline emulsion paints (bacterial mixture 2, alkaliphilic bacteria of the genus Nesterenkonia & Alkalibacterium) that were microbially contaminated in practice.

[0103] The calcium carbonate slurry was stored at 60 °C for three days for heat sterilization before adding the guanidinium salts. The treated slurry was then mixed with various concentrations of guanidine salts and homogenized. The prepared slurry was inoculated several times with bacterial strains relevant for practical use (bacterial mixture 3).

[0104] Bacteria mixture 1 :

[0105] Pseudomonas spp. (Pseudomonas oleovorans group) DSM 33933

[0106] Pseudomonas aeruginosa DSM 33935

[0107] Pseudomonas oleovorans DSM 33936

[0108] Pseudomonas putida DSM 33937

[0109] Pseudomonas aeruginosa DSM 33938

[0110] Bacteria mixture 2:

[0111] Nesterenkonia sp. DSM 108520

[0112] Nesterenkonia sp. DSM 108521

[0113] Alkalibacterium pelagium DSM 108522

[0114] Nesterenkonia massiliensis DSM 110679

[0115] Nesterenkonia sp. DSM 108519

[0116] Bacteria mixture 3:

[0117] Alcaligenes faecalis NCIMB 13145

[0118] Aeromonas hydrophila DSM 6173

[0119] Escherichia coli DSM 13631

[0120] Burkholderia cepacia DSM 9241

[0121] Staphylococcus aureus DSM 799

[0122] Pseudomonas aeruginosa DSM 50071

[0123] Pseudomonas putida DSM 13624

[0124] The inoculum was added to the respective sample at each inoculation at 2% (v / w) as a fresh cell suspension in a physiological saline solution (0.9% NaCl). The cell count of the added inoculum in Example 1 was 10 5 / ml, in examples 2 to 5 10 9 / ml, in the example 6 10 6 / ml, each consisting of equal parts of the individual bacterial strains. The cell suspension was prepared by culturing the individual bacteria for 24 hours at 30°C in liquid culture on a shaker. Müller-Hinton liquid medium served as the medium for the growth of bacteria from bacterial mixture 1. Bacteria from bacterial mixture 2 were cultivated in Müller-Hinton liquid medium, which had previously been adjusted to pH 9.5–9.7 with an alkaline buffer solution. After cultivation, the individual liquid cultures were centrifuged, and the cells were resuspended in physiological saline. To adjust the mixture to the desired cell count, the individual bacterial suspensions were diluted accordingly before combining with saline if necessary. The cell count of the inoculation suspension was determined using the chamber counting method.

[0125] In Example 1, the samples were treated once with a bacterial suspension (bacterial mixture 1) with a cell count of 10 5 / ml (2% v / w), and their growth was monitored by determining the number of viable bacteria per g of dye (colony forming units, CFU / g) in the samples over 28 days. The CFU / g was determined at each time point by taking an aliquot (1 g) from the previously homogenized sample, a serial decadic dilution series in physiological saline (0.9% NaCl), and spatula plate methods on tryptone soy agar, followed by incubation of the agar plates for 48 hours at 30 °C.

[0126] In examples 2 to 6, a so-called repetitive bacterial challenge test was carried out by repeatedly exposing the samples at specific time intervals to a bacterial suspension with a cell count of 10 9 / ml (2% v / w), and bacterial development was monitored using a semi-quantitative assessment method. After each inoculation, the samples were incubated at 30°C for 6 days (bacterial mixtures 1 and 3) or 7 and 14 days (bacterial mixture 2), and bacterial infection was assessed semi-quantitatively after each of these periods. For this purpose, an aliquot was taken from each sample after homogenization using a sterile plastic loop (10 μl) and evenly spread onto agar plates (bacterial mixtures 1 and 3 on tryptone soy agar, bacterial mixture 2 on alkaline nutrient agar DSMZ 31). The spread agar plates were then incubated for 48 hours at 30°C (bacterial mixtures 1 and 3) or 5 to 7 days (bacterial mixture 2). After incubation, the bacterial colonies grown on the agar plates were visually assessed and quantified according to the following scheme: A total of 3 vaccination cycles were performed for each repetitive stress test.

[0127] The results are shown in Tables 1 to 6:

[0128] Example 1 / Table 1 : Inoculation 2% (w / v) with bacterial mixture 1, CFU 10 5 / ml

[0129] As can be seen from the test results presented in Table 1, the addition of just 0.05 wt.% guanidine carbonate to a paint with a pH value greater than or equal to pH 8.5 leads to a significant stabilization of the paint(s) against microbial attack.

[0130] Example 2 / Table 2:

[0131] Inoculation 2% (w / v) with bacterial mixture 1, CFU 10 9 / ml

[0132] 9 pH value adjusted with NaOH

[0133] As can be seen from the test results shown in Table 2, the addition of just 0.25 wt.% guanidine hydrochloride to paint 1, which has a pH value of 8.5, or the addition of 0.25 wt.% guanidine hydrochloride to

[0134] Paint 2, which has a pH value of 9.0, leads to a significant stabilization of the paint(s) against microbial attack.

[0135] Example 3 / Table 3:

[0136] 2% (w / v) inoculation with bacterial mixture 1, CFU 10 9 / ml

[0137] The test results presented in Table 3 clearly show that for Paint 1, the addition of 0.8 wt.% guanidine hydrochloride at a pH of 7.5 and 0.15 wt.% guanidine carbonate at a pH of 9.4 led to a significant stabilization of the paint(s) against microbial attack. For Paint 2, the addition of 0.8 wt.% guanidine hydrochloride at a pH of 7.6 and 0.175 wt.% guanidine carbonate at a pH of 9.1 led to a significant stabilization of the paint against microbial attack. Example 4 / Table 4:

[0138] Inoculation 2% (w / v) with bacterial mixture 2, CFU 10 9 / ml

[0139] The test results shown in Table 4 illustrate that the addition of just 0.1 wt.% guanidine carbonate to a paint 1 with a pH value of 9.1 or higher or to paint 2 with a pH value of 8.9 or higher leads to a significant stabilization of the paint(s) against microbial attack.

[0140] Example 5 / Table 5:

[0141] Inoculation 2% (w / v) with bacterial mixture 2, CFU 10 9 / ml The test results shown in Table 5 show that for a paint with a pH value of 11.2, the addition of just 0.1 wt% guanidine carbonate leads to a significant stabilization of the paint against microbial attack.

[0142] Example 6 / Table 6

[0143] Inoculation 2% (w / v) with bacterial mixture 3, CFU 10 6 / ml

[0144] The test results shown in Table 6 illustrate that for a slurry with a pH value of 9.4, the addition of just 0.075 wt.% guanidine carbonate leads to a significant stabilization of the slurry against microbial attack.

Claims

Patent claims 1. Aqueous technical product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation, containing: (a) 0.03 to 1.4% by weight of guanidine and / or at least one salt of guanidine, the weight fraction being based on the content of guanidine in the total aqueous product, characterized in that the technical product has a pH in the range of pH 7.5 to 12.

0.

2. Technical product according to claim 1, characterized in that component (a) is contained in the technical product in the range of 0.07 to 1.2 wt.%, wherein the weight fraction relates to the content of guanidine in the total aqueous product.

3. Technical product according to claim 1 or 2, characterized in that the at least one is guanidine salt, guanidine hydrochloride and / or guanidine carbonate.

4. Technical product according to one of claims 1 to 3, characterized in that component (a) is present in the range of 0.1 to 1.0 wt.%, wherein the weight fraction relates to the content of guanidine in the total aqueous product.

6. Technical product according to one of claims 1 to 4, characterized in that it has a water content in the range of 10 to 90 wt.%.

7. Technical product according to one of claims 1 to 4, selected from a paint and a plaster containing: (a) 0.03 to 1.4% by weight of guanidine and / or at least one salt of guanidine, the weight proportion being based on the content of guanidine in the total aqueous technical product, (b) 1.0 to 85 wt.% pigment and / or filler, (c) 1 to 30 wt.% polymer dispersion, calculated as solids content and (d) 100% supplemented with water, characterized in that the technical product has a pH in the range of pH 7.5 to 12.0, or is adjusted to a pH in the range of pH 7.5 to 12.

8. Technical product according to one of claims 1 to 7, containing: (a) 0.03 to 1.4% by weight of guanidine and / or at least one salt of guanidine, the weight proportion being based on the content of guanidine in the total aqueous technical product, (b) 0.001 to 0.01 wt.% 5-chloro-2-methylisothiazolin-3-one (CMIT) and (c) 100% supplemented with water, characterized in that the technical product has a pH in the range of pH 9.0 to 11.0, or is adjusted to a pH in the range of pH 9.0 to 11.

9. Technical product according to claim 8, characterized in that the 5-chloro-2-methyl-4-isothiazolone (CMIT) has a content of 2-methyl-4-isothiazolin-3-one in the range from 0 to 2% by weight, based on the total proportion of 5-chloro-2-methyl-4-isothiazolin-3-one.

10. Technical product according to one of claims 1 to 9, characterized in that it contains one or more preservative(s) selected from the group consisting of 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 1,2-benzisothiazolin-3-one, N-butyl-1,2-benzisothiazolin-3-one, N-methyl-1,2-benzisothiazolin-3-one, octylisothiazolinone, dichlorooctylisothiazolinone, dithiobisbenzmethylamide, formaldehyde and formaldehyde releasers, quaternary ammonium compounds, bronopol, dibromonitrilopropionamide, Contains dibromodicyanobutane, iodopropynyl butylcarbamate, thiabendazole, sodium pyrithione, zinc pyrithione and o-phenylphenol in a total amount of less than 10 ppm, based on the product.

11. A process for stabilising an aqueous technical product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation against microbial attack, which comprises the process steps: (a) Providing an aqueous technical product, (b) mixing at least one salt of guanidine with the aqueous technical product and (c) optionally adjusting the pH, characterized in that the stabilized aqueous technical product has a pH in the range from pH 7.5 to 12.0, and further characterized in that the amount of the guanidine salt or guanidine salts is in the range from 0.03 to 1.4% by weight, the weight proportion relating to the content of guanidine in the total aqueous technical product.

12. The method according to claim 11, characterized in that the at least one is guanidine salt, guanidine hydrochloride and / or guanidine carbonate.

13. A process for producing an aqueous technical product selected from the group consisting of a paint, a plaster, a varnish, a glaze, a polymer emulsion, a slurry and a pigment preparation, which comprises the process steps: (a) Providing an aqueous technical product, (b) mixing at least one salt of guanidine with the aqueous technical product such that the amount of guanidine salt, based on the content of guanidine in the total aqueous technical product, is in the range of 0.03 to 1.4 wt.%, and (c) optionally adjusting the pH, characterized in that the aqueous technical product produced has a pH in the range from pH 7.5 to 12.0.

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