Aqueous industrial product stabilized against microbial contamination

Abstract

The invention relates to an aqueous industrial product selected from paints, stuccos, varnishes, glazes, polymer emulsions, slurries and pigment formulations, comprising (a) 0.03 to 1.4 wt% guanidine and / or at least one guanidine salt, where the weight ratio relates to the guanidine content throughout the aqueous industrial product, and characterized in that the industrial product has a pH in the range of pH 7.5 to 12.0. The invention further relates to a method of stabilizing an aqueous industrial product against microbial infestation comprising the following method steps: (a) providing an aqueous industrial product; (b) mixing 0.03% to 1.4% by weight of at least one guanidine salt with the aqueous industrial product, and (c) optionally adjusting the pH such that the stabilized aqueous industrial product has a pH in the range of pH 7.5 to 12.0. The invention further relates to a method for producing an aqueous industrial product.

Description

[0001] The present invention relates to an aqueous industrial product selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries, and pigment preparations, comprising (a) 0.03% to 1.4% by weight of guanidine and / or at least one guanidine salt, wherein the weight proportions relate to the guanidine content of the entire aqueous product, and characterized in that the industrial product has a pH in the range of pH 7.5 to 12.0. The present invention further relates to a method for stabilizing an aqueous industrial product against microbial infestation, comprising the following method steps: (a) providing an aqueous industrial product; (b) mixing 0.03% to 1.4% by weight of at least one guanidine salt with the aqueous industrial product, and (c) optionally adjusting the pH so that the stabilized aqueous industrial product has a pH in the range of pH 7.5 to 12.0. The present invention further relates to a method for producing an aqueous industrial product.

[0002] Industrial products, particularly water-based products such as paints, varnishes, glazes, plasters, and emulsions, are often produced using natural or biodegradable raw materials. These raw materials and the water used as solvents are often contaminated with microorganisms such as bacteria, yeasts, and fungi. If these products are produced without preservatives, they may already have high microbial counts one day after production.

[0003] In order to ensure that these products and, if appropriate, their ingredients used in production, comply with hygiene requirements and thus guarantee the shelf life of industrial products, so-called biocides are usually added to the products or directly to their ingredients.

[0004] 3-Isothiazolin-3-ones are a class of biocides used for the corrosion protection of aqueous coating compositions (such as paints, plasters, varnishes, or glazes) or their components. This substance class includes compounds with very strong antimicrobial activity, sometimes with varying spectrums of action. 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 is the so-called alkylguanidinium salts and polyguanidinium salts. For example, it is known from "Directory of microbicides for the protection of materials", Springer 2005, pp. 726 to 731 that medium-chain and long-chain guanidines and biguanides have antimicrobial effects, such as cocopropylenediamine-1,5-biguanidinium acetate, bis(guanidinooctyl)amine triacetate, poly(hexamethylenebiguanide) hydrochloride, bis(4'-chlorophenylbiguanidino)hexane, chlorhexidine digluconate, chlorhexidine diacetate.

[0006] The use of such medium-chain and long-chain guanidine compounds with other antimicrobial and / or fungicidal active substances is also known. One known example is the combination with 3-iodo-2-propynyl butylcarbamate or formaldehyde depots. For example, EP 0 891 710 A1 teaches the combined use of dodecylguanidine hydrochloride and IPBC. However, the use of dodecylguanidine salts for corrosion protection of paint compositions and polymer dispersions has been found to be problematic; for example, incompatibilities in the form of flocculation have been observed when these salts are added.

[0007] In some cases, the use of conventional biocides or preservatives is also not a consideration, as they are increasingly subject to legal restrictions.

[0008] It has therefore been proposed to provide storage-stable aqueous coating compositions of the type contemplated herein that do not include conventional preservatives by increasing their pH to a level that is effective for preventing microbial infestation. The target pH is at least 10, since at lower pH values ​​protection against microbial infestation is not sufficiently certain.

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

[0010] Alternatively, DE 10 2014 013 455 A1 and WO 2017 / 144694 A1 disclose the use of siliconates as additives for increasing the pH value.

[0011] However, a disadvantage of the above-mentioned corrosion protection methods is the relatively high pH values ​​in the coating compositions necessary for corrosion protection, which requires particular care in their operation. In addition, in recent times, infestation by alkaliphilic microorganisms, microorganisms that can survive and reproduce under alkaline conditions, has been increasingly observed in these coating compositions.

[0012] Despite the numerous known combinations of active ingredients or measures employed simultaneously, increasing regulatory restrictions have led in particular to a greater need for products that are stabilized against microbial infestation and which preferably do not contain or require only reduced amounts of conventional preservatives or biocides, such as isothiazolinones, bronopol and hydroxypyrithione.

[0013] This object is achieved by an aqueous industrial product stabilized against microbial infestation, selected from the group consisting of paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, comprising:

[0014] (a) 0.03% to 1.4% by weight, preferably 0.07% to 1.2% by weight, more preferably 0.1% to 1.0% by weight, of guanidine and / or at least one guanidine salt, wherein the weight proportions relate to the guanidine content of the entire aqueous product,

[0015] It is characterized in that the industrial product has a pH in the range of pH 7.5 to 12.0, preferably pH 8 to 11.5, more preferably pH 8.5 to 11.

[0016] Because of their composition, stabilized water-based industrial products of the present invention that resist microbial infection need significantly lower levels and in some cases do not need to be usually present in such products for the preservative of tank interior preservation. Nevertheless, due to the surprising effective interaction of guanidine or guanidine salt and the corresponding pH in the scope of pH 7.5 to 12.0, these products are characterized by excellent microbial infection resistance, especially during storage. Therefore, above-mentioned industrial products are significantly improved in terms of environmental compatibility, and also have all known properties in terms of good and safe processing properties. In addition, product of the present invention is particularly protected to resist the infection of adaptive alkaliphilic microorganisms, particularly resist alkaliphilic bacteria and resist neutrophilic to more weak alkaliphilic bacteria. Therefore, said preparation can be lower in alkalinity, which is favourable in terms of safe processing.

[0017] In a preferred embodiment of the present invention, the aqueous industrial product is substantially free of, 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, 1,2-benzisothiazolin-3-one, N-butyl-1,2-benzisothiazolin-3-one, N-methyl-1,2-benzisothiazolin-3-one, octylisothiazolinone, dichlorooctylisothiazolinone, dithiobisbenzamide, formaldehyde and formaldehyde separators, quaternary ammonium compounds, bronopol, dibromonitrilopropionamide, dibromodicyanobutane, iodopropynyl butylcarbamate, thiabendazole, sodium pyrithione, zinc pyrithione, o-phenylphenol, and combinations thereof.

[0018] "Substantially free" in this context means that the industrial product as a whole contains less than 10 ppm, preferably less than 5 ppm, more preferably less than 1 ppm in total based on the entire product.

[0019] For the purposes of the present invention, aqueous industrial products generally refer to aqueous industrial products selected from paints such as interior paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, which comprise component (a) and have a pH in the claimed range.

[0020] The aqueous industrial products according to the present invention include the following industrial products:

[0021] - coating compositions such as paints, stains, plasters, varnishes and glazes,

[0022] - polymer dispersions based on polyacrylates, polystyrene-acrylates, styrene-butadiene or polyvinyl acetate,

[0023] - Pigment preparations, master pastes and tinting pastes (Farb- und Tönpasten), and

[0024] - Slurries or pastes of raw materials, such as inorganic or organic coloring 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, hydrated calcium silicate, calcium aluminate sulfate, titanium dioxide, gypsum, bentonite, magnesium silicate, montmorillonite or talc.

[0025] More preferably, the water-based industrial product of the present invention is a paint, plaster, varnish, or glaze. The paint can be a paint for indoor use or a paint for outdoor use. The plaster can also be a plaster for outdoor use or a plaster for indoor use. The plaster can also be a sealing compound or putty for outdoor use or for indoor use.

[0026] In the present invention, the unit "% by weight" is based in each case on the entire aqueous technical product.

[0027] “At least one guanidine salt” in the context of the present invention means that the aqueous industrial product contains one or two, three, four, five or six guanidine salts, ie also mixtures of guanidine salts.

[0028] The aqueous industrial products of the present invention contain guanidine and / or at least one guanidine salt as component (a) in an amount of 0.03% to 1.4% by weight, the specified weight proportions relating to the guanidine content of the entire industrial product, to achieve stabilization against microbial infestation, particularly during storage. The amount of component (a) required for stabilization is determined by a skilled person in each case based on the respective product using familiar methods. Compared to unstabilized aqueous industrial products, i.e., products that do not contain guanidine or guanidine salts or contain too little guanidine or its salts, aqueous industrial products stabilized against microbial infestation have improved stability against microbial infestation and are therefore less susceptible to microbial infestation. In the present invention, it has been found that an amount of guanidine of up to 1.5% by weight, preferably up to 1.2% by weight, and more preferably up to 1% by weight, is sufficient to ensure stabilization of the product against microbial infestation. From a practical point of view, and especially from an economic point of view, an amount of guanidine exceeding, for example, 1.4% by weight is undesirable with regard to stabilization.

[0029] The aqueous industrial product is characterized in that component (a) is present in the aqueous industrial product in a range of 0.03% to 1.4% by weight, preferably in a range of 0.07% to 1.2% by weight, more preferably in a range of 0.1% to 1.0% by weight, wherein the specified weight proportions are based on the content of unsubstituted guanidine of the structural formula shown below in the entire aqueous industrial product:

[0030]

[0031] Therefore, in the presence of guanidine salts, the determination of guanidine content is based solely on the content associated with guanidine and does not include any counterions.

[0032] The guanidine salt that may be present in the aqueous industrial 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 bicarbonate, guanidine formate, guanidine acetate, guanidine silicate and / or guanidine citrate. At least one guanidine salt here means that one, two, three, four, five or more guanidine salts may be present.

[0033] Guanidine salts in the present invention are unsubstituted guanidine or guanidinium salts of the general formula shown below:

[0034] n X n-

[0035] wherein n is 1, 2 or 3, and wherein the counterion X n- These are, for example, chloride, carbonate, nitrate, sulfate, thiocyanate, phosphate, bicarbonate, formate, acetate or citrate.

[0036] In a preferred embodiment of the present invention, the aqueous industrial product contains guanidine hydrochloride and / or guanidine carbonate as component (a), and in a particularly preferred embodiment of the present invention, the aqueous industrial product contains guanidine carbonate as component (a).

[0037] The pH of the aqueous industrial product is generally in the range of pH 7.5 to 12. In a preferred embodiment of the present invention, the aqueous industrial product is characterized in that it has a pH in the range of 8 to 11.5, preferably in the range of 8.5 to 11. Adjusting the pH to a value in the range of 8.5 to 11 results in more skin-friendly industrial products, such as coating compositions, and thus products with further improved properties. In this way, the requirements, in particular, associated with the handling of the product of the present invention are lower.

[0038] The pH can be adjusted to the claimed range by means of measures familiar to those skilled in the art.

[0039] 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 called alkalizing agents). These compounds for adjusting the pH are known to those skilled in the art; the respective amounts used can vary within wide ranges, and the skilled person will be able to determine the range using familiar methods. Examples of alkalizing agents are:

[0040] Guanidine carbonate,

[0041] Alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide and / or potassium hydroxide,

[0042] Alkaline earth metal hydroxides, such as magnesium hydroxide, calcium hydroxide and / or barium hydroxide, ammonium hydroxide, xonotlite and / or ettringite (Ca6[Al(OH)6]2(SO4 x 26 H2O)),

[0043] Water glass, such as sodium water glass, lithium water glass and potassium water glass, or mixtures thereof,

[0044] Siliconates, such as alkali metal alkylsiliconates or alkaline earth metal alkylsiliconates, especially those of the general formula R-Si(OH)2OM A or [R-Si(OH)2O]2M E A compound wherein M A Alkali metals, such as lithium, sodium, potassium, M E is an alkaline earth metal, such as magnesium or calcium, and R is an alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl,

[0045] a buffer system, for example based on at least one phosphate or polyphosphate, preferably K 3 PO 4 or Na 3 PO 4 , and at least one alkali metal hydroxide, preferably lithium hydroxide, sodium hydroxide and / or potassium hydroxide,

[0046] Alkali metal and / or alkaline earth metal carbonates and / or bicarbonates,

[0047] Ammonia and ammonium compounds,

[0048] Amines, amino compounds and amino alcohols.

[0049] In a preferred embodiment of the invention, the pH is adjusted to the claimed range with the aid of guanidine carbonate.

[0050] In the context of the present invention, aqueous industrial products mean products which have water in an amount which makes them susceptible to infection by microorganisms.

[0051] For the purposes of the present invention, a water-based industrial product refers to a product selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, in particular water-based paints, varnishes, glazes or plasters, which has a water content of at least 10% by weight, preferably at least 15% by weight, and more preferably at least 20% by weight. The paint can be a paint for indoor use or a paint for outdoor use. The plaster can also be a plaster for outdoor use or a plaster for indoor use. In the present invention, the plaster can also be a putty for outdoor use or for indoor use. As already outlined in the introduction, such water-based industrial products are usually produced using natural or biodegradable raw materials. These raw materials and the water used as a solvent are often contaminated by microorganisms such as bacteria, yeasts and fungi. The water content in the water-based industrial product can vary within a wide range and is preferably in the range of 10% to 90% by weight, based on the entire water-based industrial product.

[0052] As already mentioned in the introduction to this specification, it has been proposed to provide storage-stable aqueous coating compositions of the type contemplated herein, such as paints and plasters, with low, preferably zero, levels of conventional preservatives by increasing their pH to effectively prevent microbial infestation. The target pH is at least 10. For example, in the prior art, such as according to EP 1 297 079 A1, the pH is increased by adding water glass. Alternatively, DE 10 2014 013 455 A1 and WO 2017 / 144694 A1 disclose the use of siliconates as pH-raising additives.

[0053] However, a disadvantage of these solutions is the necessary high pH values ​​in the coating compositions, which require particular care in their handling. Furthermore, infestation by alkaliphilic microorganisms has recently been observed to be increasing in these coating compositions. Therefore, there is a need for products, such as paints and plasters, that are stabilized against microbial infestation and that require only reduced amounts of conventional preservatives and preferably do not include conventional preservatives or biocides, such as isothiazolinones, pyrithione, and formaldehyde.

[0054] This further object is achieved by an aqueous industrial product stabilized against microbial infestation, selected from paints and plasters, comprising:

[0055] (a) 0.03% to 1.4% by weight, preferably 0.07% to 1.2% by weight, more preferably 0.1% to 1.0% by weight, of guanidine and / or at least one guanidine salt, wherein the weight proportions relate to the guanidine content of the entire aqueous technical product,

[0056] (b) 1.0% to 85% by weight of pigments and / or fillers,

[0057] (c) 1% to 30% by weight, calculated on a solids basis, of a polymer dispersion, and

[0058] (d) water to a ratio of 100% by weight,

[0059] Characterized in that the industrial product has a pH in the range of pH 7.5 to 12.0, preferably in the range of pH 8.5 to pH 11.5, or has been adjusted to a pH in the range of pH 7.5 to 12.0, preferably in the range of pH 8.5 to pH 11.5.

[0060] Surprisingly, it has been found that, with respect to this embodiment of the invention, the presence of guanidine or its salt in an aqueous industrial product, which is a paint or plaster and has a pH in the range of pH 7.5 to 12.0, preferably in the range of pH 8.5 to 11.5, provides a product that is significantly less susceptible to microbial infestation than the products known in the prior art. Due to their composition, the paint or plaster of the invention in this embodiment requires significantly lower levels of, and in a preferred embodiment of the invention, no preservatives in the form of so-called biocides, as are typically present in coating compositions (such as latex paints and plasters) for in-can corrosion protection, and still exhibits excellent storage stability. However, for outdoor use, additional biocide substances, such as algaecides and fungicides, can be added to the paint or plaster as needed to protect the film.

[0061] In this preferred embodiment of the invention, the industrial product as a paint or plaster is essentially free of, 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, 1,2-benzisothiazolin-3-one, N-butyl-1,2-benzisothiazolin-3-one, N-methyl-1,2-benzisothiazolin-3-one, octylisothiazolinone, dichlorooctylisothiazolinone, dithiobisbenzamide, formaldehyde and formaldehyde separators, quaternary ammonium compounds, bronopol, dibromonitrilopropionamide, dibromodicyanobutane, iodopropynyl butylcarbamate, thiabendazole, sodium pyrithione, zinc pyrithione, o-phenylphenol and combinations thereof.

[0062] “Substantially free” in this context means that the aqueous industrial product as a whole contains less than 10 ppm, preferably less than 5 ppm, more preferably less than 1 ppm in total based on the entire aqueous industrial product.

[0063] The guanidine salt that may be present in the aqueous industrial product as a paint or plaster is generally at least one guanidine salt selected from guanidine hydrochloride, guanidine carbonate, guanidine nitrate, guanidine sulfate, guanidine thiocyanate, guanidine phosphate, guanidine bicarbonate, 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.

[0064] In a preferred embodiment of the present invention, the aqueous industrial product as paint or plaster contains guanidine hydrochloride and / or guanidine carbonate as component (a), and in a particularly preferred embodiment of the present invention, the aqueous industrial product contains guanidine carbonate as component (a).

[0065] The pH of the aqueous industrial product in this embodiment is generally in the range of pH 7.5 to 12. In a preferred embodiment of the invention, the aqueous industrial product is characterized in that it has a pH in the range of pH 8.5 to 11.5. Adjusting the pH to a value in the range of pH 8.5 to 11.5 provides a more skin-friendly paint or plaster and thus a product with further improved properties, which is particularly advantageous in terms of its safe processing.

[0066] Waterborne industrial products as paints or plasters usually contain from 1.0% to 85% by weight of pigments and / or fillers as component (b). In a preferred embodiment of the present invention, the coating composition contains from 1% to 25% by weight of pigments and / or from 5% to 50% by weight of fillers.

[0067] The pigments used may be conventional pigment admixtures for latex paints, such as titanium dioxide, iron oxide, chromium oxide, cobalt blue, phthalocyanine pigments, spinel pigments, and nickel and chromium titanates.

[0068] The fillers present in the composition are preferably silicates, carbonates, fluorites, sulfates and oxides.

[0069] As component (c), aqueous industrial products such as paints or plasters typically contain 1 to 30% by weight, preferably 2 to 20% by weight, and more preferably 3 to 12% by weight, of a polymer dispersion, in each case calculated based on the solids content of the polymer dispersion. The polymer dispersion present in the coating composition can be any polymer dispersion known from the prior art in the field of coating or paint systems. The properties of the dispersion and the properties of the finished product produced therefrom depend primarily on the respective polymer. Such polymers are composed of various structural units, 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 aromatic compounds, 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 using ethylenically unsaturated carboxylic acids, in particular acrylic acid and methacrylic acid, and ethylenically unsaturated carboxylic acid esters, in particular acrylic acid and methacrylic acid esters having 1 to 12 carbon atoms in the alcohol group. The alcohol group of the ester may consist of a linear or branched alkyl chain, a cycloaliphatic compound, or an aromatic compound, which may also be modified with hydroxyl groups, halogen atoms, or epoxy groups. Styrene and styrene derivatives are also particularly preferably used.

[0070] As component (d), aqueous industrial products such as paints or plasters contain water to a proportion of 100%. The water content can generally vary within wide ranges and is at least 10% by weight, preferably at least 15% by weight, more preferably at least 20% by weight.

[0071] Furthermore, aqueous industrial products as paints or plasters may contain additional additives such as dispersants, thickeners, stabilizers, defoamers and / or hydrophobic agents.

[0072] The invention also relates to the use of the aqueous industrial products of the invention as paints or plasters for indoor and outdoor applications. It has been found that these are particularly suitable for indoor use due to the absence of conventional in-can preservatives.

[0073] The invention further relates to a process for producing the aqueous industrial product of the invention, which comprises mixing the components defined above.

[0074] The present invention further relates to a method for stabilizing aqueous industrial products against microbial infestation, the aqueous industrial products being selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, comprising the following method steps:

[0075] (a) Provide water-based industrial products;

[0076] (b) mixing at least one guanidine salt with the industrial product, and

[0077] (c) optionally, adjusting the pH,

[0078] It is characterized in that the stabilized aqueous industrial product has a pH in the range of pH 7.5 to 12.0, preferably pH 8 to 11.5, more preferably pH 8.5 to 11, and is further characterized in that the amount of guanidine salt is in the range of 0.03 wt.-% to 1.4 wt.-%, preferably in the range of 0.07 wt.-% to 1.2 wt.-%, more preferably in the range of 0.1 wt.-% to 1.0 wt.-%, wherein the weight proportions relate to the guanidine content in the entire aqueous industrial product.

[0079] One advantageous feature of the method of the present invention is that it can be used to produce aqueous industrial products that are stabilized against microbial infection and, due to their composition, require significantly lower levels, or in some cases no preservatives, typically present in aqueous industrial products (such as latex paints) for in-can preservation. Nevertheless, due to the surprisingly effective interaction of the at least one guanidine salt or the guanidine derived therefrom with the corresponding pH in the range of pH 7.5 to 12.0, these aqueous industrial products are characterized by excellent resistance to microbial infection, especially during storage. Consequently, the environmental compatibility of the products is significantly improved.

[0080] In step (a) of the method according to the invention, an aqueous industrial product to be stabilized against microbial infestation is provided, which is selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations. In the context of the present invention, stabilized against microbial infestation means that in the unstabilized state, in particular during storage, it has a tendency to be infested by microorganisms and thus deteriorate.

[0081] The aqueous industrial product provided in step (a) is mixed with at least one guanidine salt in step (b). The amount of guanidine salt required for stabilization is determined by the skilled person according to the respective product using familiar methods. Compared to unstabilized aqueous industrial products, i.e., products that do not contain guanidine salt or guanidine or contain too little guanidine salt or guanidine, aqueous industrial products stabilized against microbial infestation have improved stability against microbial infestation and are therefore less susceptible to microbial infestation.

[0082] Depending on the industrial product provided, the amount of guanidine salt used in process step (b) can vary within a range and is in the range of 0.03 wt. % to 1.4 wt. %, preferably in the range of 0.07 wt. % to 1.2 wt. %, more preferably in the range of 0.1 wt. % to 1.0 wt. %, wherein the weight percentages are based on the guanidine content in the entire aqueous industrial product, excluding any counterions.

[0083] In a preferred embodiment of the present invention, guanidine hydrochloride and / or guanidine carbonate is used in process step (b), and in a particularly preferred embodiment of the present invention, guanidine carbonate is used.

[0084] In process step (c) of the process for stabilizing aqueous industrial products, the pH is optionally adjusted so that the aqueous industrial product has a pH in the range of pH 7.5 to 12.0, preferably in the range of pH 8 to 11.5, more preferably in the range of pH 8.5 to 11. "Optionally" here means that, due to the composition of the product or due to the guanidine salt used, after process step (b) the pH is already in the range of pH 7.5 to 12.0, preferably in the range of pH 8 to 11.5, more preferably in the range of pH 8.5 to 11, so that adjustment is not necessary.

[0085] The present invention further relates to a method for producing an aqueous industrial product stabilized against microbial infestation, the product being selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, comprising the following method steps:

[0086] (a) providing an aqueous industrial product selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations,

[0087] (b) mixing at least one guanidine salt with the aqueous industrial product so that the amount of guanidine salt, based on the guanidine content of the entire aqueous industrial product, is in the range of 0.03% by weight to 1.4% by weight, and

[0088] (c) optionally, adjusting the pH,

[0089] It is characterized in that the finished aqueous industrial product has a pH in the range of pH 7.5 to 12.0, preferably in the range of pH 8 to 11.5, more preferably in the range of pH 8.5 to 11.

[0090] One advantageous feature of the production process of the present invention is that it can be used to produce aqueous industrial products that are already stabilized against microbial infestation and, due to their composition, require significantly lower levels, or in some cases no preservatives, typically present in these products for in-can preservation. Nevertheless, these industrial products are characterized by excellent resistance to microbial infestation, especially during storage, due to the surprisingly effective interaction of the at least one guanidine salt with the corresponding pH in the range of pH 7.5 to 12.0.

[0091] In step (a) of the production process according to the invention, an aqueous industrial product to be stabilized against microbial infestation is provided, which is selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations. In the context of the present invention, stabilized against microbial infestation means that in the unstabilized state, in particular during storage, it has a tendency to be infested by microorganisms and thus deteriorate.

[0092] The aqueous industrial product provided in step (a) is mixed with at least one guanidine salt in step (b). The amount of guanidine salt required for stabilization is determined by the skilled person using familiar methods depending on the respective product. Compared to unstabilized compositions, i.e., compositions containing no unsubstituted guanidine salt or containing too little guanidine salt, products stabilized against microbial infestation have improved stability against microbial infestation and are therefore less susceptible to microbial infestation.

[0093] Depending on the product provided, the amount of guanidine salt used in process step (b) can vary within wide ranges and is in the range of 0.03% to 1.4% by weight, preferably in the range of 0.07% to 1.2% by weight, more preferably in the range of 0.1% to 1.0% by weight, wherein the weight percentages are based on the guanidine content of the entire aqueous technical product, without including any counterions.

[0094] In a preferred embodiment of the present invention, guanidine hydrochloride and / or guanidine carbonate is used in process step (b), and in a particularly preferred embodiment of the present invention, guanidine carbonate is used.

[0095] In process step (c) of the process for producing an aqueous industrial product, the pH is optionally adjusted so that the finished product has a pH in the range of pH 7.5 to 12.0, preferably in the range of pH 8 to 11.5, more preferably in the range of pH 8.5 to 11. "Optionally" here means that, due to the composition of the product or due to the guanidine salt used, after process step (b) the pH is already in the range of pH 7.5 to 12.0, preferably in the range of pH 8 to 11.5, more preferably in the range of pH 8.5 to 11, so that adjustment is not necessary.

[0096] The present invention further relates to the use of guanidine and / or at least one guanidine salt in an amount ranging from 0.033% to 2.0% by weight, preferably from 0.07% to 1.7% by weight, and more preferably from 0.1% to 1.4% by weight, in an aqueous industrial product selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries, and pigment preparations having a pH ranging from 7.5 to 12.0, preferably from 8 to 11.5, and more preferably from 8.5 to 11, for stabilizing the aqueous product against microbial infestation, wherein the weight proportions relate to the guanidine content of the entire aqueous product, excluding any counterions. Advantageously, the use according to the invention of guanidine or at least one guanidine salt in an aqueous industrial product as defined above makes it possible to dispense with conventional preservatives typically present in such products for in-can preservation. Consequently, the environmental compatibility of the product is significantly improved. The claimed aqueous industrial product also possesses all known properties for good and safe processing. Furthermore, the products according to the invention are particularly protected against infection by adapted alkaliphilic microorganisms and against neutrophilic to less alkaliphilic microorganisms.

[0097] In a preferred embodiment, the present invention relates to an aqueous industrial product selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, comprising:

[0098] (a) 0.03% to 1.4% by weight, preferably 0.07% to 1.2% by weight, more preferably 0.1% to 1.0% by weight, of guanidine and / or at least one guanidine salt, wherein the weight proportions relate to the guanidine content of the entire aqueous technical product,

[0099] (b) 0.001 to 0.01 wt%, preferably 0.001 to 0.005 wt% of 5-chloro-2-methylisothiazolin-3-one (CMIT), and

[0100] (c) water to a ratio of 100% by weight,

[0101] Characterized in that the aqueous industrial product has a pH in the range of pH 9.0 to 11.0, or has been adjusted to a pH in the range of pH 9.0 to 11.

[0102] The advantages of this embodiment of the present invention are that, first, 5-chloro-2-methylisothiazolin-3-one is present in the industrial product as a so-called fast-kill biocide and leads to the rapid and effective killing of microorganisms present in the coating composition. In this way, for example, microorganisms introduced by the production process, such as bacteria, yeasts, and fungi, are effectively and quickly inactivated. In addition, the alkaline pH of the aqueous industrial product causes the 5-chloro-2-methyl-4-isothiazolinone to gradually degrade, so that it is only present in relatively low concentrations (if any) even after a few days, so that the product can be considered to be essentially problem-free for the end user. Since the aqueous industrial product having a pH within the range of pH 9 to pH 11 further includes at least one guanidine salt, the product is also effectively stabilized to resist possible subsequent microbial contamination during transportation and storage.

[0103] In a preferred embodiment of the present invention, the aqueous technical product is characterized in that the 5-chloro-2-methyl-4-isothiazolinone (CMIT) has a 2-methyl-4-isothiazolin-3-one content in the range of 0% by weight to 2% by weight, based on the total proportion of 5-chloro-2-methyl-4-isothiazolin-3-one.

[0104] This embodiment of the invention makes it possible to advantageously use the very potent 5-chloro-2-methyl-4-isothiazolin-3-one to obtain a product which is stabilized against microbial infestation and which, after production and storage, is particularly suitable for individuals who are highly sensitive to 5-chloro-2-methylisothiazolin-3-one or 2-methylisothiazolin-3-one.

[0105] The following examples are used to further illustrate the present invention:

[0106] In order to demonstrate the stabilization of the claimed aqueous industrial product against microbial attack by the surprising interaction between the alkaline pH range and guanidinium ions, various latex paints with different pH values ​​and calcium carbonate slurries as ingredients were mixed with different amounts of guanidine salts and examined for their stability against microbial attack:

[0107] The paints tested and their compositions are as follows:

[0108] Paint 1: a latex paint for interior use (77% pigment volume concentration) with a pH of 7.8, produced in the laboratory based on a vinyl acetate-ethylene binder without the addition of otherwise customary conventional preservatives.

[0109] Paint 2: latex paint for interior use (77% pigment volume concentration), pH 8.4, produced in the laboratory based on a styrene-acrylate binder without the addition of otherwise customary conventional preservatives.

[0110] Paint 3: Commercially available, so-called preservative-free alkaline latex paint for interior use, with a pH of 11.3 (AlpinaweissDas Original, solvent-free and preservative-free)

[0111] Calcium carbonate slurry: preservative-free calcium carbonate slurry with a solids content of 78% and a pH of 9.2.

[0112] program:

[0113] Paints 1 to 3 were mixed with various concentrations of the guanidinium salt to be tested and homogenized.

[0114] The resulting batches of paint prepared in this way were repeatedly inoculated with a mixture of different wild-type bacterial strains that are actually relevant to contamination. These bacteria had previously been isolated from commercial latex paints containing conventional preservatives that were actually contaminated with microorganisms (bacterial mixture 1, Pseudomonas spp.) and from commercial, so-called preservative-free, alkaline latex paints that were actually contaminated with microorganisms (bacterial mixture 2, alkaliphilic bacteria of the genera Nesterenkonia & Alkalibacterium).

[0115] The calcium carbonate slurry was heat sterilized by storing it at 60°C for three days before adding the guanidine salt. The treated slurry was then mixed with different concentrations of guanidine salt and homogenized. The prepared slurry was inoculated repeatedly with a practically relevant bacterial strain (bacterial mixture 3).

[0116] Bacterial mixture 1:

[0117] Pseudomonas spp. (Pseudomonas oleovorans group) DSM 33933

[0118] Pseudomonas aeruginosa DSM 33935

[0119] Pseudomonas oleovorans DSM 33936

[0120] Pseudomonas putida DSM 33937

[0121] Pseudomonas aeruginosa DSM 33938

[0122] Bacterial mixture 2:

[0123] Nesterenkonia sp. DSM 108520

[0124] Nesterenkonia sp. DSM 108521

[0125] Alkalibacterium pelagium DSM 108522

[0126] Nesterenkonia massiliensis DSM 110679

[0127] Nesterenkonia sp. DSM 108519

[0128] Bacterial cocktail 3:

[0129] Alcaligenes faecalis NCIMB 13145

[0130] Aeromonas hydrophila DSM 6173

[0131] Escherichia coli DSM 13631

[0132] Burkholderia cepacia DSM 9241

[0133] Staphylococcus aureus DSM 799

[0134] Pseudomonas aeruginosa DSM 50071

[0135] Pseudomonas putida DSM 13624

[0136] In each inoculation, the inoculum was added to the respective sample at 2% (v / w) as a fresh cell suspension in physiological saline solution (0.9% NaCl). The cell count of the added inoculum was 10 in Example 1. 5 / ml, and 10 in Examples 2 to 5 9 / ml, in Example 6 it is 10 6 / ml, each consisting of a respective bacterial strain in equal parts. Cell suspensions were prepared by culturing the respective bacteria in liquid culture on a shaker at 30°C for 24 hours. The culture medium used to culture the bacteria from bacterial mixture 1 was Müller-Hinton liquid medium. The bacteria from bacterial mixture 2 were cultured in Müller-Hinton liquid medium that had been previously adjusted to pH 9.5-9.7 with an alkaline buffer solution. After cultivation, the respective liquid cultures were centrifuged and the cells resuspended in physiological saline. To adjust the mixture to the desired cell count, the respective bacterial suspensions were diluted accordingly with saline solution before merging, if necessary. The cell count of the inoculum was determined in each case by chamber counting.

[0137] In Example 1, the sample was counted as 10 5 The samples were inoculated once with a 2% v / w bacterial suspension (bacterial cocktail 1), and growth was monitored over 28 days by determining the number of viable bacteria per gram of lacquer (colony-forming units, CFU / g). Each time, CFU / g was determined by removing an aliquot (1 g) of the previously homogenized sample and running a tenfold serial dilution series in physiological saline solution (0.9% NaCl), streaking the sample onto tryptone soy agar, and incubating the agar plates at 30°C for 48 hours.

[0138] In Examples 2 to 6, the cells were counted as 10 9 A so-called repeated bacterial stress test was performed by repeatedly inoculating samples at specific time intervals with a bacterial suspension of 100 μg / ml (2% v / w) and monitoring bacterial evolution using a semi-quantitative evaluation 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 in each case after these times. To do this, an aliquot (10 µl) was removed from each sample after homogenization using a sterile plastic inoculating loop and streaked evenly onto agar plates (bacterial mixtures 1 and 3 on tryptone soy agar, bacterial mixture 2 on DSMZ 31 basic nutrient agar). The streaked agar plates were then incubated at 30°C for 48 hours (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 evaluated and quantified according to the following protocol:

[0139]

[0140] A total of three inoculation cycles were performed in each replicate stress experiment.

[0141] The results are shown in Tables 1 to 6:

[0142] Example 1 / Table 1:

[0143] Inoculate with 2% (w / v) bacterial mixture 1, 10 5 CFU / ml

[0144]

[0145] From the experimental results shown in Table 1 it can be inferred that the addition of even 0.05% by weight of guanidine carbonate to a paint having a pH greater than or equal to pH 8.5 leads to a significant stabilization of the paint against microbial attack.

[0146] Example 2 / Table 2:

[0147] Inoculate with 2% (w / v) bacterial mixture 1, 10 9 CFU / ml

[0148]

[0149] 1) Adjust pH with NaOH

[0150] From the experimental results shown in Table 2 it can be seen that even the addition of 0.25% by weight of guanidine hydrochloride to Paint 1 at pH 8.5 or to Paint 2 at pH 9.0 leads to a significant stabilization of the paints against microbial attack.

[0151] Example 3 / Table 3:

[0152] Inoculate with 2% (w / v) bacterial mixture 1, 10 9 CFU / ml

[0153]

[0154] The experimental results shown in Table 3 clearly show that in the case of Paint 1, the addition of 0.8% by weight of guanidine hydrochloride at pH 7.5 resulted in a significant stabilization of the paint against microbial infestation, and the addition of 0.15% by weight of guanidine carbonate at a pH of 9.4 resulted in a significant stabilization of the paint against microbial infestation. In the case of Paint 2, the addition of 0.8% by weight of guanidine hydrochloride at a pH of 7.6 resulted in a significant stabilization of the paint against microbial infestation, and the addition of 0.175% by weight of guanidine carbonate at a pH of 9.1 resulted in a significant stabilization of the paint against microbial infestation.

[0155] Example 4 / Table 4:

[0156] Inoculate with 2% (w / v) bacterial mixture 2, 10 9 CFU / ml

[0157]

[0158] The experimental results shown in Table 4 show that even the addition of 0.1% by weight of guanidine carbonate to Paint 1 at a pH above 9.1 or to Paint 2 at a pH above 8.9 leads to a significant stabilization of the paints against microbial attack.

[0159] Example 5 / Table 5:

[0160] Inoculate with 2% (w / v) bacterial mixture 2, 10 9 CFU / ml

[0161]

[0162] The experimental results shown in Table 5 show that, in the case of a paint having a pH of pH 11.2, the addition of 0.1% by weight of guanidine carbonate already leads to a significant stabilization of the paint with respect to microbial attack.

[0163] Example 6 / Table 6

[0164] Inoculate with 2% (w / v) bacterial mixture 3, 10 6 CFU / ml

[0165]

[0166] The experimental results shown in Table 6 show that, in the case of a slurry having a pH of pH 9.4, the addition of 0.075% by weight of guanidine carbonate already leads to a significant stabilization of the slurry towards microbial infestation.

Claims

1. A water-based industrial product selected from the group consisting of paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, comprising: (a) 0.03% to 1.4% by weight of guanidine and / or at least one guanidine salt, wherein the weight proportions relate to the guanidine content of the entire aqueous product, It is characterized by The industrial product has a pH in the range of pH 7.5 to 12.

0.

2. The industrial product according to claim 1, characterized in that Component (a) is present in the technical product in an amount ranging from 0.07% to 1.2% by weight, wherein the weight proportions relate to the guanidine content of the entire aqueous product.

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

4. The industrial product according to any one of claims 1 to 3, characterized in that Component (a) is present in an amount in the range of 0.1% to 1.0% by weight, wherein the weight proportions relate to the guanidine content of the entire aqueous product.

5. The industrial product according to any one of claims 1 to 4, characterized in that It has a water content in the range of 10% to 90% by weight.

6. The industrial product according to any one of claims 1 to 4, selected from paints and plasters, comprising: (a) 0.03% to 1.4% by weight of guanidine and / or at least one guanidine salt, wherein the weight proportions relate to the guanidine content of the entire aqueous technical product, (b) 1.0% to 85% by weight of pigments and / or fillers, (c) 1% to 30% by weight, calculated on a solids basis, of a polymer dispersion, and (d) water to a ratio of 100% by weight, It is characterized by The industrial product has a pH in the range of pH 7.5 to 12.0, or has been adjusted to a pH in the range of pH 7.5 to 12.

7. The industrial product according to any one of claims 1 to 7, comprising: (a) 0.03% to 1.4% by weight of guanidine and / or at least one guanidine salt, wherein the weight proportions relate to the guanidine content of the entire aqueous technical product, (b) 0.001% to 0.01% by weight of 5-chloro-2-methylisothiazolin-3-one (CMIT), and (c) water to a ratio of 100% by weight, It is characterized by The industrial product has a pH in the range of pH 9.0 to 11.0, or has been adjusted to a pH in the range of pH 9.0 to 11.

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

9. The industrial product according to any one of claims 1 to 9, characterized in that It contains less than 10 ppm in total, based on the product, of one or more preservatives 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, dithiobisbenzamide, formaldehyde and formaldehyde releasers, quaternary ammonium compounds, bronopol, dibromonitrilopropionamide, dibromodicyanobutane, iodopropynyl butylcarbamate, thiabendazole, sodium pyrithione, zinc pyrithione and o-phenylphenol.

10. A method for stabilizing an aqueous industrial product against microbial infestation, the aqueous industrial product being selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, the method comprising the following method steps: (a) Provide water-based industrial products; (b) mixing at least one guanidine salt with the aqueous industrial product, and (c) optionally, adjusting the pH, It is characterized by The stabilized aqueous industrial product has a pH in the range of pH 7.5 to 12.0, and It is further characterized in that the amount of guanidine salt is in the range from 0.03% to 1.4% by weight, wherein the weight proportions relate to the guanidine content of the entire aqueous technical product.

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

12. A method for producing an aqueous industrial product selected from paints, plasters, varnishes, glazes, polymer emulsions, slurries and pigment preparations, comprising the following method steps: (a) Provide water-based industrial products; (b) mixing at least one guanidine salt with the aqueous industrial product so that the amount of guanidine salt, based on the guanidine content of the entire aqueous industrial product, is in the range of 0.03% by weight to 1.4% by weight, and (c) optionally, adjusting the pH, It is characterized by The aqueous industrial product is manufactured to have a pH in the range of pH 7.5 to 12.0.

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