EP1835806A2

EP1835806A2 - Antimicrobial solid matter preparations

Info

Publication number: EP1835806A2
Application number: EP05849257A
Authority: EP
Inventors: Peter Wachtler
Original assignee: Lanxess Deutschland GmbH
Current assignee: Lanxess Deutschland GmbH
Priority date: 2005-01-13
Filing date: 2005-12-16
Publication date: 2007-09-26
Also published as: MX2007008468A; NO20074085L; DE102005001566A1; WO2006074788A2; US20080009532A1; AU2005324894A1; CA2593827A1; WO2006074788A3

Abstract

The invention relates to antimicrobial, aqueous preparations of water-insoluble solid matter, containing 1,2-benzisothiazolin-3-on (BIT) and having at least one additional biocide effect, characterised by the rapid onset-effect having a long-term effect despite reduced concentration of the used biocide mixtures. Said preparation is also ecofreindly.

Description

Antimicrobially finished solid preparations

The present invention relates to antimicrobially finished aqueous preparations of water-insoluble solids containing l, 2-benzisothiazolin-3-one (BIT) and at least one further biocidal active substance, and to a process for the preparation of these preparations and to the use of active substance mixtures of 1,2-benzisothiazolinone 3-one and at least one other biocidal active ingredient for the protection of preparations of water-insoluble solids.

Aqueous preparations, such as suspensions or dispersions of water-insoluble solids, such as minerals, fillers or pigments, are, due to their good processability or the possibility of specific adjustment of customer-specific substance parameters, a raw material component that is widely used in practice. These products are characterized in that in them a water-insoluble solid component with the addition of a dispersing aid and optionally other additives in water so distributed, i. is suspended, dispersed or slurried, the mixtures are formed with a solids content of 40-80%. Used in large quantities, e.g. Kaolin or calcium carbonate slurries in the paper industry as a filler in the wet-end or as a constituent of coating colors in the production of coated papers. Notwithstanding the fact that such aqueous suspensions or dispersions are mainly inorganic compounds by weight, practical experience shows that even such products, under appropriate circumstances, may be exposed to massive attack by microorganisms, which may not tolerable changes in material properties. Known effects of microbial attack of such aqueous suspensions or dispersions of minerals, fillers or pigments are e.g. Viscosity changes, discoloration or odor quality reductions. Due to the economic consequences of missing lots, e.g. In the paper industry, the provision of a technology which reliably prevents the above-described disadvantages of product damage caused by microbial spoilage is thus absolutely necessary.

There has been no lack of attempts in the past to provide technologies for preventing the microbial or bacterial spoilage of mineral slurries.

The most promising method for ensuring an acceptable microbiological quality of mineral slurries over their entire life cycle (production, storage, transport, consumption) is the addition of preservatives or biocidal products. By accompanying measures in the field of industrial hygiene, the activity of the biocidal products used can optionally be supported and optimized in a manner known to the person skilled in the art. However, all previous attempts to produce microbiologically stable mineral slurries by adding preservatives and biocidal products have one or the other disadvantage:

Dazomet, a biocide that works well in principle, undergoes rapid degradation with release of toxic and strong-smelling gases, especially in alkaline-adjusted products (e.g., talc or calcium carbonate lurries).

Bronopol, an excellent bactericide, is degraded faster under the harsh conditions (high pH and temperatures) of slurry production and processing under unfavorable conditions than effect can occur.

Formaldehyde or the formaldehyde releasers derived therefrom are a good-acting and sufficiently stable preservative, in particular against bacteria. Due to toxicological concerns and legal regulations, however, this proven preservative can no longer be used in many countries.

Benzisothiazolinone, a very stable and easy-to-use preservative, has an unbalanced spectrum of activity, especially against certain types of bacteria dominating in mineral slurries, and is also a relatively slow-acting biocide. To make matters worse in this drug that the required high dosages are associated with a relatively high price, so that benzisothiazolinone for economic reasons, no outstanding position in the conservation of mineral slurries of the type described above can take.

There has thus continued to be a need to provide new and more reliable methods for controlling undesirable microbial growth events in the production, storage, transportation and processing of aqueous formulations of water-insoluble solids, e.g. aqueous preparations of minerals, fillers or pigments, in particular those with higher pH values, such as e.g. Calcium carbonate or talcum lurries. It is generally desirable to achieve the highest possible biocidal effect with the available active ingredients on the one hand and on the other hand only relatively small amounts of the active ingredients to use. However, 1,2-benzisothiazolin-3-one, which is stable even under extreme pH and temperature conditions, has as an individual component too low an economically not competitive activity.

The invention 'therefore an object of the invention to provide an aqueous preparation of water-insoluble solids, which avoids the above-mentioned problems and very well during the entire manufacturing process, and the subsequent logistical processing, is protected against microbial attack and thus ensures a perfect microbiological quality of the products until final consumption.

It has now surprisingly been found that mixtures based on 1,2-benzisothiazolin-3-one (benzisothiazolinone, BIT) and at least one further antimicrobially active component to unexpectedly good results in the preservation of aqueous preparations of water-insoluble solids, especially difficult to protect Preparations such as calcium carbonate or talcum lurries lead. The aforementioned products are difficult to preserve reliably and long-lasting with the known container preservatives, because the specified pH and temperature conditions make special demands on the stability of the preservatives to be used.

The present invention therefore antimicrobially finished aqueous compositions of water-insoluble solids containing a mixture of 1,2-Benzisothia- zolin-3-one and at least one other biocidal active ingredient.

As further biocidal active substances, besides l, 2-benzisothiazolin-3-one, the following compounds are preferably suitable:

Isothiazolinone from the series 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 2-methyl-4-isothiazolin-3-one (MIT);

Formaldehyde;

Formaldehyde releasing agents based on O-formals, such as e.g. Benzylhemiformal, ethylene glycol bis-hemiformal, ethylene glycol hemiformal;

Formaldehyde releasing agents based on N-formals, such as e.g. 3-dimethylol-5,5-dimethyl-dendoin (DMDMH), tetramethylolacetylenediurea (TMAD), N, N'-dimethylolurea, N-methylolurea, 4,4-dimethyl-1,3-oxazolidine; Diazolidinyl urea, imidazolidinyl urea, 3,3'-methylene-bis (5-methyloxazolidine), 1,3,5-hexahydotriazine, sodium (hydroxymethyl) glycinate, 7a-ethyl dihydro-1H, 3H, 5H-oxazolo [3 , 4-c] oxazole;

bromine-containing biocides such as 2-bromo-2-nitropropane-1,3-diol (Bronopol) and dibromodicyanobutane (DBDCB);

o-phenylphenol. The preparations according to the invention particularly preferably comprise mixtures of 1,2-benzothiazolin-3-one with the other biocidal active substances 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one on.

The aqueous preparations according to the invention are preferably suspensions, dispersants or slurries.

The solid, water-insoluble solids contained in the preparations according to the invention are preferably natural or synthetic minerals, fillers or pigments based on natural or synthetic raw materials such as e.g. Aluminum hydroxide, aluminum silicate, titanium dioxide, iron oxide, kaolin, calcium carbonate or talc.

The preparations according to the invention preferably have a content of water-insoluble constituents of from 40 to 80% by weight.

A mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one in the weight ratio of 1-50 g (1-chloro-2-methyl-4-isothiazolin-3-one) is preferably used in the preparations according to the invention as another biocidal active substance. 50 ppm), in particular from 5 to 30 g (5 to 30 ppm), based on 1 ton of the preparations according to the invention.

The concentrations of the biocidal active substances in the preparations according to the invention are in the range from 10 to 500 ppm for 1,2-benzisothiazolin-3-one, and in the range from 1 to 5000 ppm in each case for the second component or the sum of the further components on the total weight of the preparation.

The proportions of 1,2-benzisothiazolin-3-one (BIT) and the second or further active compound component (s) can vary over a wide range. In the preparations according to the invention, the ratio benzisothiazolinone (BIT) to the second or the sum of the further active ingredient component (s) is normally in a weight ratio of 100: 1 to 1: 100, preferably 50: 1 to 1:50, particularly preferably 10: 1 to 1:10.

The preparations according to the invention are preferably aqueous suspensions, dispersions or slurries of calcium carbonate or talc or kaolin in water, the solids content being 40-80% by weight and the content of the total of biocidal active substances being 1-5000 ppm, in each case based on the total weight of the preparation.

The aqueous preparations according to the invention have a high resistance to infestation by microorganisms, in particular by aerobic or anaerobic bacterial species, and thus allow trouble-free handling of the products during production, storage, transport and final processing. Examples of types of microorganisms that can colonize aqueous suspensions, dispersions or slurries of minerals, fillers or pigments are, in particular, aerobic and anaerobic bacterial species. Without limiting the following types are mentioned:

Alcaligenes such as Alcaligenes faecalis Bacillus, such as Bacillus firmus

Corynebacterium such as Corynebacterium aquaticum Desulfovibrio desulfuricans Enterobacter such as Enterobacter aerogenes,

Enterococci such as Enterococcus faecalis Escherichia such as Escherichia coli, Proteus such as Proteus vulgaris Pseudomonas such as Pseudomonas aeruginosa, Schewanella such as Schewanella putrefaciens Serratia such as Serratia marescens Staphylococcus such as Staphylococcus aureus.

The antirnikrobiell equipped preparations according to the invention are characterized by the following characteristics:

• faster entry

• good long-term effect despite low concentration of the biocide mixtures used

• Low application toxicity to humans and mammals

• good compatibility.

In addition, the antimicrobially finished preparations according to the invention are surprisingly distinguished by the fact that the incorporated biocidal active compounds have an unexpectedly high, synergistic increase in activity in specific mixing ratios. It follows that the required for the antimicrobial equipment use concentrations of the active ingredient components of the invention, compared with the necessary concentrations in the case of the respective individual active ingredients, can be reduced. This is extremely advantageous in terms of economic, ecological, and aannwweenndduunnggsteentechniehngchennes GGeessiicchhttssppuunnkktteenn and represents a contribution to increasing the preservation quality. The preparations according to the invention may additionally contain one or more other biocides

Contain active ingredients. As preferred mixing partners, the following compounds may be mentioned:

Benzalkonium chloride benzyl alcohol

2,4-dichlorobenzyl

Bromochlorodimethylhydantoin

Butyl, ethyl, methyl, propylparaben

Cetylpyridinium chloride Dazomet

2,2-dibromo-3-nitrilopropionamide (DBNPA)

dodecylguanidine

Methylene-bis-thiocyanate

Di-decyl-di-methyl-ammonium chloride 2-phenoxyethanol

2-phenoxypropanols

Phenyl-ethyl-alcohol

Poly (hexamethylene biguanide) hydrochloride (PHMB)

The antimicrobially finished aqueous formulations according to the invention can be prepared by dispersing, suspending or slurrying water-insoluble solids, preferably minerals, pigments or fillers, with the addition of a dispersing agent and optionally further additives in water and with the biocidal active mixture of 1,2-benzene - Added sothiazolin-3-one and at least one other biocidal compound, optionally with the addition of one or more solvents and optionally further antimicrobial compounds.

Another object of the present invention is the use of a mixture of 1,2-benzisothiazolin-3-one and at least one other biocidal active ingredient from the series of isothiazolinones, formaldehyde and Formaldehydabspalter, the bromine-containing biocides and o-phenylphe- nol for the protection of aqueous preparations of water-insoluble solids, inns in particular suspensions ^•, dispersions and slurries of minerals, pigments or fillers.

Very particularly preferred is the use according to the invention of a mixture of 1,2-

Benzisothizolin-3-one and at least one other biocidal active ingredient from the series of n isothiazolinones, formaldehyde and Formaldehydabspalter, the bromine-containing biocides and o-phenylphenol for the protection of aqueous calcium carbonate or talc slurries. Preferred isothiazolinones, formaldehyde releasers and bromine-containing biocides are the abovementioned compounds used in the preparations according to the invention.

The mixtures to be used according to the invention can be incorporated in the preparations to be protected during the production process of these preparations, during storage or before and / or during the transport of the preparations, in a manner known per se.

Depending on their respective physical and / or chemical properties or the specific operational requirements of the preservation problem to be solved, the application of the biocidal active substance mixtures to be used according to the invention can be carried out either separately in the form of a metered addition of the individual active ingredients to the preparation to be protected, as appropriate Preservation task an individual adjustment of the concentration ratio can be made, or it can be done the addition of a finished active ingredient mixture. For this purpose, the biocidal active substance mixture can be converted beforehand into a customary formulation, such as e.g. in a solution, emulsion, suspension, a powder, a foam, in pastes, granules, aerosols and in finely encapsulated form in polymeric substances, transferred.

These formulations can be prepared in a manner known per se, for example by mixing the mixture or the individual active substances contained therein with extenders, ie liquid solvents, liquefied gases under pressure and / or solid carriers, if appropriate using surface-active agents, ie emulsifiers and / or or dispersants and / or foam-forming agents. In the case of the use of water as extender, for example, organic solvents may additionally be used as auxiliary solvents. Suitable liquid solvents are essentially: alcohols, such as butanol or glycol, and their ethers and esters, ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents, such as dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide, as well as water; By liquefied gaseous diluents or carriers are meant those liquids which are gaseous at normal temperature and under normal pressure, for example aerosol propellants, such as halogenated hydrocarbons as well as butane, propane, nitrogen and carbon dioxide; suitable solid carriers are: for example ground natural minerals, such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals, such as finely divided silica, alumina and silicates; as solid carriers for granules are: for example, broken and fractionated natural rocks such as calcite, marble, pumice, sepiolite, dolomite and synthetic granules of inorganic and organic flours and granules of organic material such as sawdust, coconut shells, corncobs and tobacco stalks; suitable emulsifiers and / or foam-forming agents are: for example, nonionic and anionic emulsifiers, such as polyoxygenated ethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, for example alkylaxylpolyglycol ethers, alkylsulfonates, alkylsulfates, arylsulfonates and protein hydrolysates; suitable dispersants are: for example Ligninsulfitablaugen and polyacrylates.

Adhesives and thickeners such as carboxymethylcellulose, methylcellulose, natural and synthetic, powdery, granular or latex-like polymers can be used in the formulations, such as gum arabic, polyvinyl alcohol, polyvinyl acetate, and natural phospholipids such as cephalins and lecithins and synthetic phospholipids. Other additives may be mineral and vegetable oils.

The active compound combinations to be used according to the invention prepared as described above comprise the active compounds in concentrations of 5 to 50% by weight, preferably 5 to 30% by weight, calculated as the sum of all active ingredient components.

The use concentrations of the active compound combinations to be used depend on the nature and occurrence of the microorganisms to be controlled, the initial microbial load and the expected storage time of the suspensions or dispersions of minerals, fillers or pigments to be protected. The optimum amount can be determined by preliminary tests and test series on a laboratory scale as well as by supplementary operating tests. In general, the use concentrations in the range of 0.01 to 5 wt .-%, preferably from 0.05 to 1.0 wt .-% of the active ingredient mixtures, based on the suspensions or dispersions of minerals, fillers or pigments to be protected.

The following example documents the good microbiological stability of the suspensions or dispersions of minerals, pigments or fillers protected by the mixtures according to the invention:

example

Against certain, in particular practice-relevant germs such. Pseudomonas sp. , the mineral slurries according to the invention are distinguished by a surprisingly good antimicrobial resistance. In particular, the use according to the invention of the biocidal active ingredient components results in a synergistic effect, i. the effectiveness of the mixtures is better than would be deduced from the effectiveness of the individual components.

Microbiological stress test

The Microbiological Stress Test verifies the susceptibility of water-based systems to microbial attack and the effects of preservatives. For this purpose, the preservatives are incorporated in defined concentrations in the water-based systems. To simulate practical conditions, depending on the medium to be tested before the actual preservation experiment carried out storage at elevated temperatures (eg 7 days 40 ⁰ C, 3 days 60 ⁰ C oa) to the tested preservatives under realistic conditions as possible to get. After completion of the preliminary work, contamination with microorganisms of a defined type occurs at weekly intervals over a test period of a maximum of 6 weeks. It is determined by counting the number of germs 2-3 or 7 days after each contamination whether complete kill or at least inhibition of proliferation of the microorganisms introduced has occurred in comparison with the non-conserved control samples.

Knowing the prevalent microorganism populations in mineral suspensions and dispersions, a mixture of the following bacterial species was used for the test:

Pseudomonas aeruginosa

Pseudomonas fluorescens Pseudomonas oleovorans

Pseudomonas rubescens

Pseudomonas pruning

Alcaligenes faecalis

Citrobacter friend Corynebacterium sp. Very good effectiveness is achieved if the preserved samples cause a kill of the introduced microorganisms even after 6 cycles of contamination. A satisfactory effect is present when a greatly reduced microbial level is observed compared to the unpreserved sample.

Results

With a Calciumcarbonatslurry (70 - 75% solids) was carried out according to the above scheme preservation stress test. After incorporation of the respective biocides at the indicated concentrations, the samples were exposed for 3 days at 6O ⁰ C to a thermal load to labile active ingredients to identify in the biocidal products already in this phase of the experiment by subsequent ineffectiveness.

table

As can be seen from the above table, by adding the mixtures according to the invention of benzisothiazolinone and a second biocidal component, the action of benzisothiazolinone can be considerably enhanced, resulting in antimicrobial, in particular more antibacterially resistant suspensions, dispersions or slurries of minerals, fillers or pigments. Despite a reduced compared to the single active ingredient BIT drug concentration in the specified mixtures (see table) achieved a substantially improved overall effect, i. full efficacy will be maintained against all microorganism species used for testing for a 6 week test period.

Claims

claims

1. Antimicrobially finished aqueous compositions of water-insoluble solids containing a mixture of l, 2-benzisothiazolin-3-one and at least one other biocidal active ingredient.

2. Preparation according to claim 1, characterized in that the water-insoluble solids are natural or synthetic minerals, fillers or pigments.

3. Preparation according to at least one of claims 1 and 2, characterized in that as further biocidal active ingredient at least one compound selected from the series of isothiazolinones, formaldehyde, Formaldehydabspalter, the bromine-containing biocides and o-

Phenylphenol is included.

4. Preparation according to at least one of claims 1 to 3, characterized in that a mixtures of l, 2-benzisothiazolin-3-one with 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4 Isothiazolin-3-one is included.

5. A preparation according to at least one of claims 1 to 4, characterized in that it is a dispersion, suspension or slurry of aluminum hydroxide, aluminum silicate, titanium dioxide, iron oxide, kaolin, calcium carbonate and / or talc containing a mixture of l, 2 -Bisisothiazolin-3-one with 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one.

6. A process for the preparation of a preparation according to claim 1, characterized in that water-insoluble solids are dispersed with the addition of a dispersing aid and optionally further additives in water and with a biocidal active ingredient mixture of l, 2-benzisothiazolin-3-one and at least one further biocidal compound if appropriate with the addition of one or more solvents and, if appropriate, further antimicrobially active compounds.

7. Use of a mixture of l, 2-benzisothiazolin-3-one and at least one further biocidal active ingredient from the series of isothiazolinones, formaldehyde and Formaldehydabspalter, the bromine-containing biocides and o-phenylphenol for the protection of aqueous preparations of water-insoluble solids from attack and destruction by microorganisms.

8. Use according to claim 7, characterized in that a mixture of 1,2-benzisothiazolin-3-one with 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin 3-on is used.

9. Use of a mixture of l, 2-benzisothiazolin-3-one with 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one for the protection of dispersions, suspensions or Slurries of natural or synthetic minerals, fillers or pigments against infestation and destruction by microorganisms.

10. A process for the protection of aqueous preparations of water-insoluble solids from attack and destruction by microorganisms, characterized in that the preparation either with a mixture of l, 2-Benzisothizolin-3-one and at least one further biocidal active ingredient from the series of Isothiazolinone , Formaldehyde and Formaldehydabspalter, the bromine-containing biocides and o-phenylphenol, and optionally adjuvants and additives, or the individual active ingredients and optionally auxiliaries and additives added separately to the preparation, wherein the mixing or metering during the manufacturing process of the preparation or to manufacture

Preparation can be done.