DE3828755A1 - Antimicrobial compounds for controlling undesired microbial growth and/or corrosion caused by microbes in water-bearing devices - Google Patents

Abstract

There are described antimicrobial compounds for controlling undesired microbial growth and/or corrosion caused by microbes in water-bearing devices, which have at least one biocidal moiety and at least one further moiety which has an affinity for the surface of the water-bearing device. A particularly good activity is shown by compounds of the formula <IMAGE> in which R1 to R3 are lower alkoxy groups having 1 to 4, in particular 1 or 2, C atoms, R4 to R6 are C1- to C24-alkyl or -aryl groups, with the proviso that at least one of the groups R4 to R6 is an alkyl group having 10 to 24 C atoms and X is phosphorus or nitrogen and Y- is an anion from the group comprising halide, nitrate, nitrite, cyanide or else an organic anion, and n has a value from 2 to 10, and by compounds of the formula <IMAGE> in which R1 to R3 are lower alkoxy groups having 1 to 4, in particular 1 or 2, C atoms, R4 to R6 are C1- to C24-alkyl or -aryl groups and n has a value from 2 to 10.

Description

The invention relates to new antimicrobial compounds to combat unwanted microbial growth and / or microbially caused Corrosion (biofouling) in water-bearing Devices.

Such devices are in particular pipelines made of plastic and / or metals, containers or other water containing or in contact with it upcoming devices that are subject to corrosion Microbial exposure (biofouling) can.

Varnishes or paints with biocide additives are indeed known that such devices for a certain Protect time from microbial corrosion. Such Varnishes or paints are often difficult to apply, e.g. B. inside narrow tubes, and expensive. Their effects are often too weak, because the biocide content is covered by paint films and can become ineffective. Paint with regulated, as continuous as possible biocide release are only with a few, but chemically bound hydrolyzable agents known. In addition to mechanical Methods for cleaning z. B. are of hulls chemical agents such as chlorination of water in use. However, the latter can e.g. B. with plastic Water pipes for the formation of chlorinated hydrocarbons lead with carcinogenic effects. In The presence of ammonia becomes dangerous chloramines formed, ozone or quaternary ammonium compounds  disintegrate quickly and / or do not adhere sufficiently long on the device to be protected.

It was found that when on the with Water or aqueous systems in permanent or intermittent surfaces mono- or multi-molecular layer of one Biocides is applied to the surface partially or completely covered and on the or the surfaces by covalent and / or ionic and / or hydrogen bonds and / or further ties, in the most general case by mixed bonds is fixed so that a cleavage or hydrolysis of the biocide from the surface in neutral, weakly acidic or weakly basic Area not or in negligible Dimensions, but in any case so little Measures are taken that the split off or hydrolyzed Amount of biocide no biostatic or exerts biocidal action, so that on or deposited on the treated surfaces, deposited or adsorbed microorganisms killed by contact with the fixed biocide or be hindered in their growth.

The antimicrobial compounds according to the invention to combat unwanted microbial growth and / or microbial corrosion in water-carrying devices are characterized that these connections have at least one biocidal part of the molecule and at least one other part of the molecule with an affinity for adhesion Have surface of the water-carrying device.

In particular, the biocidal part of the molecule quaternary ammonium residue or phosphonium residue  or a triorganotin residue, especially a Tri (alkyl and / or aryl) tin residue, and the Molecular residue with affinity for the water-bearing Device a silane compound.

Such compounds preferably have the Formulas

Compounds of formula I are those in which R₁ to R₃ are lower alkoxy groups having 1 to 4, in particular 1 or 2, carbon atoms, R₄ to R₆ are C₁ to C₂₄ alkyl or aryl groups with the proviso that at least one of the groups R₄ to R₆ is an alkyl group with 10 to 24 carbon atoms, and X is phosphorus or nitrogen and Y ^- an anion from the group consisting of halide, nitrate, nitrite, cyanide or an organic anion, and n has the value 2 to 10, and in particular those in which R₁ to R₃ methoxy or ethoxy groups, R₄ and R₆ a C₁ to C₄ alkyl group or phenyl group and R₅ a C₁₀-C₂₄ alkyl group or R₄ and R₆ a C₁₀ or C₂₄ alkyl group and then Rgruppe a C₁- bis C₄-alkyl group or phenyl group and n = 1 to 4 and Y = halogen.

Compounds of formula II are those in which R₁ to R₃ are lower alkoxy groups having 1 to 4, in particular 1 or 2, C atoms, R₄ to R₆ are C₁ to C₂₄ alkyl or aryl groups and n is 2 to 10, and in particular those in which R₄ to R₆ is a butyl or phenyl radical, n is 1 to 10 and in particular 1 to 4, and R₁ to R₃ are lower alkoxy groups having 1 to 4, in particular 1 or 2, carbon atoms.

Exemplary experiments with biocidal compounds with and without adhesion group on surfaces, in this Case of a cellulose surface, are in the reproduced in the following table. It appears, that most of the compounds known as biocides are also active in the bound state, while others, namely hydroxyaniline and tetrachloroaniline, which directly on the protoplasm of Microorganisms work, are not active.  

Table I

The biggest activity is with mercury and organotin compounds achieved that corresponds to that solved by the Connections as such is achieved. Farther the effect can be demonstrated if treated and untreated paper strips be buried in the ground and at 30 ° C stand in 95% relative humidity be left. During untreated paper strips already dismantled after 3 days, becomes a paper with the surface bound Aminophenylmercury acetate even after 17 days only weakly attacked. When using of this paper with fixed aminophenylmercury acetate as a bacterial filter for air filtration it is found that after prolonged incubation no bacteria appeared on the agar test.

An important application of the invention Connections used is in the Disinfection of water. Here, in particular quaternary ammonium or phosphonium compounds tied on microbeads made of glass and Packs of such pearls as filters for the Water disinfection needed. It was found, that complete disinfection regarding Escherichia coli already with a bed height of 6 cm is reached.

The preferred compounds consisting of a silane residue and a quaternary ammonium residue are e.g. B. prepared by reacting q- chloro-propyltrimethoxysilane with tertiary amines, preferably those with 10 to 24 carbon atoms, and in particular with 19 to 21 carbon atoms. The long-chain aliphatic group determines the wettability of the treated surface, but also the antimicrobial effect.

To use the compounds, an aqueous Solution of the connections made and so impregnated the device and then thermally treated in air at around 100 ° C. Here, the alkoxy groups of the sil portion hydrolyze and form a siloxane network that up 120 ° C and above is stable to hydrolysis. Such molecular parts bind particularly well on glass. In addition to covalent bonding with silanol groups on the surface can also electrostatic and mixed bonds occur. This will create multiple layers of the biocide formed what is beneficial for the effect.

Since most microbes carry a negative charge, can quaternary ammonium or phosphonium compounds tighten them and kill them if necessary. However, such molecules can also pass through Serum or proteins can be inactivated. thats why it often prefers to use non-polar biocides Tack surfaces of fixtures. Such Connections are e.g. B. triorganotin compounds, which is often cheaper for the tick according to the invention than the ammonium or phosphonium compounds are. These are made by implementation from Z. B. trimethoxyvinylsilane and tributyltin or triphenyltin hydride.  

The compounds used according to the invention are so far the chemicals used for this purpose such as chlorine, sodium hypochlorite, chlorine dioxide and Ozone or the free phenolic compounds, quaternary ammonium compounds, amines and superior to organic sulfur compounds as they adhere better and therefore have a lasting effect exercise and are relatively inexpensive. In particular, the use for disinfection preferred by water and achieves a substantial Cleaning effect.

The effect of some of these compounds is said to following using two typical examples below Use of an onium or tin compound are explained.

Example 1

Glass microspheres approximately 100 µm in diameter were impregnated with a quaternary ammonium compound, namely dimethyloctadecyl [3- (trimethoxysilyl) propyl] ammonium chloride, and then treated with air at 100 ° C. The coated glass balls were filled into a glass tube with an inside diameter of 2 cm and a length of about 6 cm, which was also coated on the inside like the glass balls. A continuous stream of a germ suspension (E. coli) with about 10 3 K ml ^{-1 was} passed through this module over 6 days. The flow velocity related to the empty pipe cross section was 0.64 10 ^-4 ms ^-1 . The germ concentration after the module was practically zero over the entire period. An analog reference module with untreated balls and uncoated pipe was operated in parallel. The relative germ concentration after the module was about 0.2, which is due to the adsorption effect of the glass surface on the bacteria.

After that the flow was interrupted the germ suspension remained in the module for 1 day stand. After that she was on the remaining Residual germs examined. In the suspension of the Modules with the coated balls could not reproducible germs are detected, the relative germ in the reference module was concentration 0.18.

Example 2

The same experiment as in Example 1 was carried out, however, the glass balls and the inside were the glass tube with a tin connection, namely 3- (triethoxysilyl) ethyl-tri-n-butylstannane, coated. The relative germ concentration behind the module with the coated balls was during the entire test duration about 1, d. H. there were de facto no germs killed. After that the Flow also interrupted for 1 day and after this 1 day standing time the relative germ concentration certainly. There were only a few germs left detectable.

The different results with the onium or the tin compound are probably based on the fact that the onium compound has a strong adsorption effect exerts on the germs, so that these also under flow conditions are absorbed and thus killed can be. In the case of the tin compound  this adsorption does not take place because it is completely is apolar. For this reason, under flow conditions no germs are killed either. However, if you leave the system at rest, you can the germs sediment and become on contact killed with the surface. This effect the non-adsorption is in the case of prevention absolutely desirable by biofouling. For this The tin compounds are basically the quaternary Consider onium compounds. You own a double effect, namely non-adsorption or the prevention of adsorption combined with a high antimicrobial Effect.

Claims (6)

1. Antimicrobial compounds for combating undesirable microbial growth and / or microbially caused corrosion in water-carrying devices, characterized in that these compounds have at least one biocidal part of the molecule and at least one other part of the molecule with an affinity to the surface of the water-carrying device. 2. Antimicrobial compounds according to claim 1, characterized, that the biocidal part of the molecule is a quaternary ammonium residue or phosphonium residue or a triorganotin residue and the part of the molecule with affinity to the surface the water-carrying device a silane compound is. 3. Antimicrobial compounds according to claim 1 or 2, characterized by the formula wherein R₁ to R₃ are lower alkoxy groups having 1 to 4, in particular 1 or 2, carbon atoms, R₄ to R₆ are C₁ to C₂₄ alkyl or aryl groups with the proviso that at least one of the groups R₄ to R₆ is an alkyl group having 10 to 24 Is C atoms, and X is phosphorus or nitrogen and Y ^- an anion from the group consisting of halide, nitrate, nitrite, cyanide or an organic anion and n has the value 2 to 10. 4. Antimicrobial compounds according to claim 1 or 2, characterized by the formula wherein R₁ to R₃ are lower alkoxy groups with 1 to 4, in particular 1 or 2 carbon atoms, R₄ to R₆ are C₁ to C₂₄ alkyl or aryl groups and n has the value 2 to 10. 5. Antimicrobial compounds according to claim 3, wherein R₁ to R₃ methoxy or ethoxy groups, R₄ and R₆ a C₁ to C₄ alkyl group or phenyl group and R₅ a C₁₀-C₂₄ alkyl group or R₄ and R₆ a C₁₀ or C₂₄ alkyl group and then R₅ is a C₁ to C₄ alkyl group or phenyl group and n = 1 to 4 and Y is halogen. 6. Antimicrobial compounds according to claim 4, characterized in that R₄ to R₆ is a butyl or phenyl radical, n is 1 to 10 and in particular 1 to 4, and R₁ to R₃ have the meaning given in claim 4.