DE102012210294A1 - Anti-fouling additives, process for their preparation and their use in coatings - Google Patents

Abstract

The present invention relates to anti-fouling additive comprising at least a) a modified or unmodified silica, silicate or silica gel having a mean particle size d50 of 100-500 microns, b) a modified or unmodified silica, silicate or silica gel having an average particle size d50 from 20-70 microns and c) a modified or unmodified silica, silicate or silica gel having an average particle size d50 of <20 microns. The anti-fouling additive according to the invention is prepared by mixing. The anti-fouling additive can be used in paints.

Description

The present invention relates to anti-fouling additives, a process for their preparation and their use in coatings.

For the purposes of the present invention, the term anti-fouling additives, instead of the commonly used term anti-fouling additive, is used to emphasize that the effectiveness of the additives according to the invention is based solely on a physical effect in terms of foul-release coatings and easy-to -Clean coatings and no biocides or biocidal substances are necessary.

Out EP2281855A1 Antifouling additives are known which function according to the chemical action principle, ie the antifouling mechanism of action is based on the release (leaching) of biocides, in particular natural biocides, such as menthol, from the coating.

Furthermore, anti-fouling additives are known, based on physical principles of action, for example, the structuring of the paint surface for the production of air-holding surfaces in WO9729157A1 . EP1570980A1 . JP10025427A and JP09053612A , The use of finely divided particles or fibers forms a ternary air-water-paint barrier, which should have a positive effect on the adhesion properties of the surface. A disadvantage is that the air can be kept in moving objects (eg ships) only for a short period of time during immersion in the water in the laminar boundary layer, so that a long-term effectiveness based on this coating is not given.

JP08268377A describes as an alternative the supply of air by means of compressors, which is of little relevance for certain applications.

Out CN101792534A For example, micro- and nanostructured surfaces with anti-fouling efficiencies are known which are made by molding the surface (molds). In this way, natural antifouling surfaces (eg sharkskin), which are based on physical principles of action, can be ideally reshaped. Although the antifouling effectiveness of the artificial surfaces is proved, but the transmission on the technical scale based on this technology is not given.

Furthermore, are off DE102006030055A1 Nanostructured coating systems based on nanoscale hydrophobic particles are known. However, these are less stable under mechanical stress, since the functionalized particle systems are not firmly fixed in the binder, so that no long-term efficacy is given. Furthermore, the surface topographies generated by means of monomodal nanoparticles are unsuitable for physical growth reduction in the sense of the invention.

Numerous scientific publications describe physical fouling based on hierarchically structured surfaces, e.g. "Surface modification approaches to control marine biofouling", Scardino, Advances in Marine Antifouling Coatings and Technology, 2009, Woodhead Publishing, pp. 644-692. From this it is known that for the antifouling effect, the surface should be provided with structuring in different orders of magnitude. Due to the diversity of organisms living in the sea, it is not possible to achieve an anti-fouling effect, in the broader sense, a fouling effect, with only one structure. So for the defense against microorganisms to use other structure sizes compared to macroorganisms such as shells and algae. The stated orders of magnitude vary from a few nanometers to hundreds of micrometers.

EP1591509A1 describes the generation of a lotus surface by ceramic hollow microspheres, which in turn are occupied by nanoparticles (eg aluminum oxides, alumina hydrates, titanium dioxides, zirconium dioxides) and has improved lifetimes in the sense of conventional lotus effect applications (facades, buildings, roofs).

Also describes EP1283077A1 a self-cleaning surface of depressions and elevations produced by particles, which are equipped with antimicrobial properties, ie active ingredients, so that the effect is not based solely on physical effects.

US20080241408A1 describes the generation of a lotus surface, ie a liquid-repellent surface, with structurings in the range of <500 nm by using two sizes of colloidal particles in the range of 15-2000 nm and 1-200 nm, respectively.

Further functionalities can be generated here by modifying the particles with hydrocarbons (eg alkyl chains), silanes or biocides ( EP1882722A1 ).

The production of microstructured surfaces based on natural models can be done in addition to the use of particles by using fibers that are based on natural herbal models such as hothouse seeds or animal models, such as sea lions. WO2007108679A1 describes the use of μm fibers, which are sprayed onto the wet paint by electrostatic charging and thus produce a sea lion-like surface structure. It is known to the person skilled in the art that this type of application is impractical for large-scale implementation.

Furthermore, structured surfaces can also be produced by polymer modification ( Development and Testing of Hierachically Wrinkled Coatings for Marine Antifouling, Efimenko, Applied Materials & Interfaces, Vol. 5, 1031-1040, 2009 ).

The object of the present invention is to provide a fouling-reducing additive which, when incorporated into coatings, achieves a fouling-reducing action based on non-toxic physical principles of action, and the fouling-reducing coating can also be produced on an industrial scale by conventional methods. Furthermore, the antifouling effectiveness of the applied cured coating on the basis of any binder system should be possible by adjusting the concentrations used and optimization parameters known to the person skilled in the art.

A further object of the present invention is to provide growth-reducing additives which are largely or completely biodegradable and / or biologically harmless.

A further object is to provide fouling-reducing additives which ensure sufficient fouling-protection protection both during travel and during lay periods of vessels or other objects in contact or coming into contact with water, in particular seawater.

Another object of the present invention is to provide antifouling additives which, incorporated in selected coatings, can provide easier fouling. This easier cleaning is based on the fact that by using said additives, a microstructured surface is produced and the number of adhesion points is reduced. In addition, the flow dynamics of the coatings can be positively influenced, which also leads to an easier cleaning.

For the purposes of the present invention, biodegradability or biodegradability refers to the capacity of organic chemicals for biodegradation, ie their decomposition by living beings or their enzymes. Ideally, this chemical metabolism goes all the way to mineralization, breaking the organic compound down to inorganic matter such as carbon dioxide, oxygen, and ammonia. This process can be analyzed analytically, e.g. be recorded by the indication of the half-life. If a complete biodegradation within the meaning of the above definition is not possible, it is ensured that the additives used in the context of the invention are harmless. Ie. The additives have no toxic or hazardous effect on other organisms. The additives do not accumulate or only slightly in the water and are not environmentally hazardous.

Harmful to the environment in the sense of the present invention refers to the property of substances and substance mixtures which can directly or indirectly damage humans or animals, plants, their communities and habitats, and in particular the soil, or irreversibly change them in the long term.

For the purposes of the present invention, the property of the coatings provided with antifouling additives refers to the settling of fouling organisms, i. To reduce microfouling and macro-fouling compared to the same coating not containing the anti-fouling additives.

• a) eine modifizierte oder nicht modifizierte Kieselsäure, Silikat oder Kieselgel mit einer mittleren Partikelgröße d50 von 100–500 µm, vorzugsweise von 100–300 µm,
• b) eine modifizierte oder nicht modifizierte Kieselsäure, Silikat oder Kieselgel mit einer mittleren Partikelgröße d50 von 20–70 µm, vorzugsweise von 20–50 µm und
• c) eine modifizierte oder nicht modifizierte Kieselsäure, Silikat oder Kieselgel mit einer mittleren Partikelgröße d50 von <20 µm, vorzugsweise von 10 nm–10 µm.

The invention relates to a fouling-reducing additive containing at least

• a) a modified or unmodified silica, silicate or silica gel having an average particle size d 50 of 100-500 μm, preferably of 100-300 μm,
• b) a modified or unmodified silica, silicate or silica gel having an average particle size d50 of 20-70 microns, preferably 20-50 microns and
• c) a modified or unmodified silica, silicate or silica gel having an average particle size d50 of <20 .mu.m, preferably of 10 nm-10 .mu.m.

The antifouling additive may be free of biocides or biocidal substances.

The silicas can be precipitated and / or pyrogenic silicas.

For example, precipitated silicas according to EP 1398301 A2 . EP 1241135 A1 . EP 1648824 A1 . EP 0798348 A1 . EP 0341383 A1 or EP 0922671 A1 be used.

Precipitated or pyrogenic silicic acids and silica gels are already used as additives (eg for rheology control or matting) in paints, so that easy incorporation and uniform distribution of the additives can be ensured in the paint by the methods known to the person skilled in the art without a complete reformulation of the formulation of the coating system is necessary.

The three silicic acids, silicates or silica gels a) -c) can be mixed with one another in variable ratios. The mixing ratios and the amounts used can have a considerable influence on the resulting structures and thus on the anti-fouling effect. The mixing ratio of the silicic acids, silicates or silica gels a): b): c), based on the mass, may preferably be 3: 2: 1 to 0.5: 0.5: 1.

Particularly preferably, the mixing ratio of the silicic acids, silicates or silica gels a): b): c), based on the mass, 1: 1: 1; 3: 2: 1 or 6: 4: 5. Depending on the chosen binder system, other than the mentioned mixing ratios may prove to be advantageous.

In a preferred embodiment of the invention, the silicas, silicates or silica gels a) -c) can be used modified. The modification can be carried out by surface modification or impregnation of the particles.

Methods of surface modification may include any functionalizations with silanes, silicones, fatty acids, carbon compounds, polymers and the like resulting in covalent bonding or even physical bonding, e.g. based on van der Waals forces, between the solid particles and the stock system. However, it should be noted that this functionalization does not produce any antimicrobial properties in the sense of a biocidal effect, but only a modification of the surface properties (for example hydrophobicity) is achieved. As silanes for surface modification, it is possible, for example, to use the following silanes, individually or as a mixture:

Organosilanes (RO) ₃ Si (C _n H _{2n + 1} ) and (RO) ₃ Si (C _n H _2n-1 ) where R is the same or different and is alkyl, such as methyl, ethyl, n-propyl, i-propyl or butyl is and n = 1-20,

Organosilanes R ' _x (RO) _y Si (C _n H _{2n + 1} ) and R' _x (RO) _y Si (C _n H _2n-1 ) with the same or different and R and alkyl, such as methyl, ethyl, n-propyl , i-propyl or butyl, R 'is the same or different and is alkyl, such as methyl, ethyl, n-propyl, i-propyl, butyl or cycloalkyl and n = 1-20; x + y = 3, x = 1 or 2, y = 1 or 2,

Halogenorganosilane X ₃ Si (C _n H _{2n + 1} ) and X ₃ Si (C _n H _2n-1 ) with X = Cl or Br; n = 1-20,

Halogenorganosilane X ₂ (R ') Si (C _n H _{2n + 1} ) and X ₂ (R') Si (C _n H _2n-1 ) with X = Cl or Br, R '= alkyl, such as methyl, ethyl, n Propyl, i-propyl, butyl or cycloalkyl and n = 1-20,

Haloorganosilanes X (R ') ₂ Si (C _n H _{2n + 1} ) and X (R') ₂ Si (C _n H _2n-1 ) where X = Cl or Br; R 'is the same or different and is alkyl, such as methyl, ethyl, n-propyl, i-propyl, butyl or cycloalkyl and n = 1-20,

Organosilane (RO) ₃ Si (CH ₂ ) _m -R "
R is the same or different and is alkyl, such as methyl, ethyl, n-propyl, i-propyl or butyl, m = 0.1-20, R "= methyl, aryl, such as -C ₆ H ₅ or substituted phenyl radicals, C ₄ F ₉ , OCF ₂ -CHF-CF ₃ , C ₆ F ₁₃ , OCF ₂ CHF ₂ , S _z - (CH ₂ ) ₃ Si (OR) ₃ with z = 1-10, SH, NR ¹ R ² R ³ with R ¹ = alkyl or aryl; R ² = H, alkyl or aryl; R ³ = H, alkyl, aryl, benzyl, C ₂ H ₄ NR ⁴ R ⁵ with R ⁴ = H or alkyl and R ⁵ = H or alkyl,

Organosilanes (R ') _x (RO) _y Si (CH ₂ ) _m -R''
R is the same or different and is alkyl, such as methyl, ethyl, n-propyl, i-propyl or butyl, R 'is the same or different and is alkyl, such as methyl, ethyl, n-propyl, i-propyl, Butyl or cycloalkyl, x + y = 3, x = 1 or 2, y = 1 or 2; m = 0.1 to 20, R "= methyl, aryl, such as C ₆ H ₅ or substituted phenyl, C ₄ F ₉ , OCF ₂ -CHF-CF ₃ , C ₆ F ₁₃ , OCF ₂ CHF ₂ , S _z - (CH ₂ ) ₃ Si (OR) ₃ with z = 1-10, SH, NR ¹ R ² R ³ with R ¹ = alkyl or aryl; R ² = H, alkyl or aryl; R ³ = H, alkyl, aryl, benzyl, C ₂ H ₄ NR ⁴ R ⁵ with R ⁴ = H or alkyl and R ⁵ = H or alkyl,

Halogenorganosilane X ₃ Si (CH ₂ ) _m -R ⁶
with X = Cl or Br, m = 0.1-20, R = methyl, aryl, such as C ₆ H ₅ or substituted phenyl radicals, C ₄ F ₉ , OCF ₂ -CHF-CF ₃ , C ₆ F ₁₃ , O- CF ₂ -CHF ₂ , SH or S _z - (CH ₂ ) ₃ Si (OR) ₃ with z = 1-10 and R is the same or different and alkyl, such as methyl, ethyl, n-propyl, i-propyl or butyl is

Halogenorganosilane RX ₂ Si (CH ₂ ) _m R ⁶
X = Cl or Br, m = 0.1-20, R is the same or different and is alkyl, such as methyl, ethyl, n-propyl, i-propyl or butyl, R ⁶ = methyl, aryl, such as C ₆ H ₅ or substituted phenyl radicals, C ₄ F ₉ , OCF ₂ -CHF-CF ₃ , C ₆ F ₁₃ , O-CF ₂ -CHF ₂ , SH or S _z - (CH ₂ ) ₃ Si (OR) ₃ with z = 1-10,

Halogenorganosilane R ₂ XSi (CH ₂ ) _m R ⁶
X = Cl or Br, m = 0.1-20, R is the same or different and is alkyl, such as methyl, ethyl, n-propyl, i-propyl or butyl, R ⁶ = methyl, aryl, such as C ₆ H ₅ or substituted phenyl radicals, C ₄ F ₉ , OCF ₂ -CHF-CF ₃ , C ₆ F ₁₃ , O-CF ₂ -CHF ₂ , SH or S _z - (CH ₂ ) ₃ Si (OR) ₃ with z = 1-10,
Silazanes R ⁷ R ⁸ ₂ SiNHSiR ⁸ ₂ R ⁷ where R ⁷ , R ⁸ = are the same or different and are alkyl, vinyl or aryl,

mit
R⁹ = Alkyl,
R¹⁰ = substituiertes oder unsubstituiertes Alkyl, Aryl oder H
R¹¹ = substituiertes oder unsubstituiertes Alkyl oder Aryl
R¹² = substituiertes oder unsubstituiertes Alkyl, Aryl oder H
Y = CH₃, H, C_vH_2v+1 mit v = 1–20, Si(CH₃)₃, Si(CH₃)₂H, Si(CH₃)₂OH, Si(CH₃)₂(OCH₃) oder Si(CH₃)₂(C_vH_2v+1)
wobei
ein R¹⁰ oder R¹¹ oder R¹² (CH₂)_v–NH₂ sein kann und v = 1–20, m’ = 0,1,2,3, ... 100.000, n’ = 0,1,2,3, ... 100.000, u’ = 0,1,2,3, ... 100.000 ist.Cyclic polysiloxanes D3, D4, D5 and their homologs, where D3, D4 and D5 are cyclic polysiloxanes having 3, 4 or 5 units of the type -O-Si (CH ₃ ) ₂ , eg octamethylcyclotetrasiloxane (D4)

With
R ⁹ = alkyl,
R ¹⁰ = substituted or unsubstituted alkyl, aryl or H
R ¹¹ = substituted or unsubstituted alkyl or aryl
R ¹² = substituted or unsubstituted alkyl, aryl or H
Y = CH ₃ , H, C _v H _{2v + 1 where} v = 1-20, Si (CH ₃ ) ₃ , Si (CH ₃ ) ₂ H, Si (CH ₃ ) ₂ OH, Si (CH ₃ ) ₂ ( OCH ₃ ) or Si (CH ₃ ) ₂ (C _v H _{2v + 1} )
in which
R ¹⁰ or R ¹¹ or R ^{12 can be} (CH ₂ ) _v -NH ₂ and v = 1-20, m '= 0,1,2,3, ... 100,000, n' = 0,1,2 , 3, ... 100,000, u '= 0,1,2,3, ... 100,000.

The surface-modifying agents which may be used are preferably the following: octyltrimethoxysilane, octyltriethoxysilane, hexamethyldisilazane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, dimethylpolysiloxane, nonafluorohexyltrimethoxysilane, tridecaflourooctyltrimethoxysilane or tridecaflourooctyltriethoxysilane.

Hexamethyldisilazane octyltriethoxysilane or dimethylpolysiloxanes can be used with particular preference.

The modification can be achieved by impregnation with, for example, silicone oil, polyethylene glycol, polysaccharides, block copolymers, caprolactones, lactide and glycolide polymers, polyanhydrides, polyesters, hydroxybutyric acids, polyphosphazenes, polyphosphoesters, polyvinyl alcohol, polyvinyl acetate, alginate, gelatin, agar or pectin , The modified silicas, silicates or silica gels can be incorporated into the coating systems analogously to the pure silicas, silicates or silica gels, with additional functionalities being produced which have a soil-reducing effect or can modify the processing properties in the varnish. In the case of the modified silicic acids, silicates or silica gels, they can be almost completely embedded in the binder so that the silicic acid / silica or silica gel surface is not exposed and existing surface functionalities can not be effective.

In a preferred embodiment of the present invention, the silicas, silicates or silica gels a-c may be a mixture of unmodified and modified silicas. One, two or three of the three silicic acids, silicates or silica gels may be present modified a-c.

In addition to the average diameter, the silicas and silicates used can have a grindometer value of 10 to 45 μm, preferably 20 to 43 μm, and / or a tamped density of 50 to 350 g / l, preferably 50 to 300 g / l, and / or an oil number of 180 to 360 g / 100 g and / or a DBP number of 200 to 450 g / 100 g, preferably 320 to 400 g / 100 g, and / or a BET of 100 to 600 m ² / g, preferably 200 to 550 m ² / g, particularly preferably from 300 to 550 m / g, very particularly preferably from 350 to 2500 m / g, and / or a total pore volume of from 6 to 14 ml / g (0.0042-414 MPa, 140 °). Most preferably, the silicas and silicates have several of the aforementioned physicochemical properties in combination, and more preferably, all the aforementioned properties in combination.

Depending on the concentration, incorporation of the microstructured particles into the coating formulation on the surfaces coated with these coating formulations may produce microstructuring that affects biofilm growth and macro-fouling.

The BET surface area is important in order to achieve sufficient reinforcement in the paint system.

The anti-fouling additive according to the invention may be a powder, preferably free-flowing powder. This means that the flowability of the product measured with the outlet funnels after DIN 53492 preferably has the value 1. The fouling-reducing additives according to the invention can therefore be processed and transported particularly well.

Another object of the invention is a process for the preparation of the growth-reducing additive according to the invention, which is characterized in that a modified or unmodified silica, silicate or silica gel a) having a particle size of 100-500 .mu.m, preferably 100-300 microns , a modified or unmodified silica, silicate or silica gel b) having a particle size of 20-70 microns, preferably from 20-50 microns and a modified or unmodified silica, silicate or silica gel c) having a particle size of <20 microns, preferably from 10nm-10μm, mixes. The silicas, silicates or silica gels a-c may be modified. The modification can be carried out by surface modification or impregnation of the particles.

The mixing can be carried out, for example, in a kneader, paddle dryer, tumble mixer, vertical mixer, paddle mixer, Schugimischer, cement mixer, Gerickekontimischer, Eirichmischer and / or Silomischer.

The temperature in the mixing unit can be between 5 ° C and 120 ° C.

The mixture can be done under air atmosphere. The anti-fouling additive according to the invention can be used in coating systems, preferably paints.

The coating system comprising the anti-fouling additive according to the invention can be applied to the surface of the objects to protect the surface of objects which come in contact or come into contact with water, in particular seawater.

• a) eine modifizierte oder nicht modifizierte Kieselsäure, Silikat oder Kieselgel mit einer mittleren Partikelgröße d50 von 100–500 µm, vorzugsweise von 100–300 µm,
• b) eine modifizierte oder nicht modifizierte Kieselsäure, Silikat oder Kieselgel mit einer mittleren Partikelgröße d50 von 20–70 µm, vorzugsweise von 20–50 µm und
• c) eine modifizierte oder nicht modifizierte Kieselsäure, Silikat oder Kieselgel mit einer mittleren Partikelgröße d50 von <20 µm, vorzugsweise von 10 nm–10 µm enthält.

Another object of the invention is a paint, which is characterized in that this at least

• a) a modified or unmodified silica, silicate or silica gel having an average particle size d 50 of 100-500 μm, preferably of 100-300 μm,
• b) a modified or unmodified silica, silicate or silica gel having an average particle size d50 of 20-70 microns, preferably 20-50 microns and
• c) contains a modified or unmodified silica, silicate or silica gel having an average particle size d50 of <20 microns, preferably from 10 nm-10 microns.

The paint of the invention may be free of biocides or biocidal substances.

The modified or unmodified silicas, silicates or silica gels a) -c) can be dispersed in any desired order in the finished paint formulation.

Another object of the invention is a paint, which is characterized in that it contains the fouling-reducing additive according to the invention.

The lacquer according to the invention may contain 1-40% by weight, preferably 10-20% by weight, of growth-reducing additive, based on the lacquer.

The anti-fouling additive can be dispersed with moderate shear stress in the finished paint formulation and the paint can then be applied as a last coat using standard methods. Rollers as well as syringes can be used for this purpose. In addition to the selection of the particles used, the mixing ratio, the particle concentration and the coating formulation, the application technique can also have an influence on the resulting structure.

It has also been shown that an exposure or activation of the modified silicic acid / silicate or silica gel surfaces and thus of the existing surface-active groups can take place by utilizing the hydrolysis taking place upon contact with water. For this purpose, the silicas, silicates or silica gels, for example, be first modified or impregnated with a water-soluble polymer and then incorporated into the coating systems by the said methods. Upon contact with water, i. During the intended use, the water-soluble polymer can be dissolved by the water diffusion taking place in the paint network. The water-soluble polymers used can be biodegradable and not environmentally hazardous. The detachment of the polymer from the surface of the particles simultaneously removes the paint on the particle, thereby exposing the particle surface. The particle remains sufficiently surrounded by the coating matrix, so that the silica, silicate or silica gel are not exposed from the paint system and can escape from the paint matrix. By means of this mechanism it is possible to selectively distribute functionalities in the paint, so that when using pure silicic acid / silicate or silica gel particles in a hydrophobic coating system, for example, hydrophilic spots can be produced in a hydrophobic matrix. These alternating surfaces in turn have particularly good anti-fouling properties. Furthermore, it is possible by means of this mechanism specifically to expose the functionalities of the modified silicic acid / silicate or silica gel particles after incorporation into the paint matrix on the surface.

The paints prepared in this way show both in the laboratory bioassay against the test microorganism Ps.atlantica and in the field trial a fade-reducing effect in comparison to the reference system without the addition of the structuring elements. Another advantage that results from using the additives described is the increase in mechanical strength, as well as the possibility of Rheologieeinstellung.

With the fouling-reducing additive according to the invention, it is possible to coat all objects which are exposed to the danger of biofouling. These are in particular sport boats, commercial ships, submerged in water structures and facilities such. As jetties, quay walls, oil rigs, etc., navigation marks, other buoys or probes.

measurement methods

Analysis of the physico-chemical properties of silica, silicates or silica gels

Determination of the DBP number:
The DBP absorption (DBP number), which is a measure of the absorbency of a porous particle, is based on the norm DIN 53601 determined as follows:
12.50 g of powdery or spherical carrier material with 0-10% moisture content (if necessary, the moisture content is set by drying at 105 ° C in a drying oven) are in the kneader chamber (Article number 279061) of the Brabender Absorptometer '' E '' given (without Attenuation of the output filter of the torque transducer). In the case of granules, the sieve fraction of 3.15 to 1 mm (stainless steel sieves Retsch) is used (by gently pressing the granules with a plastic spatula through the sieve with 3.15 mm pore size). With constant mixing (rotary speed of the kneader blades 125 rpm) is added dropwise at room temperature through the "Dosimaten Brabender T 90/50" dibutyl phthalate at a rate of 4 ml / min in the mixture. The mixing takes place with only a small force requirement and is tracked on the basis of the digital display. Towards the end of the determination, the mixture becomes pasty, which is indicated by a steep increase in the power requirement. With a display of 600 digits (torque of 0.6 Nm), both the kneader and the DBP metering are switched off by an electrical contact. The synchronous motor for the DBP supply is coupled to a digital counter so that the consumption of DBP in ml can be read.

mit
DBP = DBP-Aufnahme in g/(100g)
V = Verbrauch an DBP in ml
D = Dichte von DBP in g/ml (1,047 g/ml bei 20 °C)
E = Einwaage an Kieselsäure in g
K = Korrekturwert gemäß Feuchtekorrekturtabelle in g/(100g)The DBP recording is given in units of [g / (100g)] without decimal places and is calculated according to the following formula:

With
DBP = DBP uptake in g / (100g)
V = consumption of DBP in ml
D = density of DBP in g / ml (1.047 g / ml at 20 ° C)
E = weight of silica in g
K = correction value according to humidity correction table in g / (100g)

The DBP image is defined for anhydrous, dried support materials. When using moist support materials, in particular precipitated silicas or silica gels, the correction value K must be taken into account for calculating the DBP absorption. This value can be determined from the following correction table, eg. For example, a water content of the support material of 5.8% would mean a 33 g / (100 g) addition for DBP uptake. The moisture of the carrier material is determined according to the method described below "Determination of moisture or dry loss". Table: Moisture correction table for dibutyl phthalate uptake - anhydrous -

Determination of the oil number

The determination of the oil number takes place after DIN EN ISO 787-5 with linseed oil.

Determination of moisture or dry loss

The moisture or dry loss (TV) of support materials is based on ISO 787-2 after 2 hours of drying at 105 ° C determined. This drying loss consists predominantly of water moisture.

execution

In a dry weighing glass with ground cover (diameter 8 cm, height 3 cm) 10 g of the powdery, spherical or granular material are weighed to exactly 0.1 mg (weight E). The sample is dried with the lid open for 2 h at 105 ± 2 ° C in a drying oven. The weighing glass is then closed and cooled to room temperature in a desiccator cabinet with silica gel as drying agent. The weighing glass / beaker is weighed to the nearest 0.1 mg to determine the weight A on the precision balance. Determine the humidity (TV) in% according to TV = (1 - A / E) x 100, where A = weight in g and E = weigh in g.

Average particle size d ₅₀

The determination of the particle distribution of the product systems according to the invention is carried out according to the principle of laser diffraction on a laser diffractometer (Horiba, LA-920). To determine the particle size of powders, a dispersion having a weight fraction of about 1% by weight of SiO _{2 is} prepared by stirring the powder in water.

Immediately following the dispersion, the particle size distribution is determined from a partial sample of the dispersion with the laser diffractometer (Horiba LA-920). For the measurement a relative refractive index of 1.09 has to be chosen. All measurements are carried out at room temperature. The particle size distribution and the relevant variables such. The mean particle size d ₅₀ , for example, is automatically calculated and graphed by the device. The instructions in the operating instructions must be observed.

Determination of the BET surface area

The specific nitrogen surface area (hereinafter referred to as the BET surface area) of the pulverulent, approximately spherical particles or granular silicic acid is based on ISO 5794-1 / Annex D with the device TRISTAR 3000 (Micromeritics) after the multipoint determination according to DIN-ISO 9277 determined.

Determination of tamped density

The determination of the tamped density was carried out according to DIN EN ISO 787-11 ,

Determination of the total pore volume

The total pore volume is determined by means of mercury porosimetry. The method is based on the Hg intrusion according to DIN 66133 (with a surface tension 480 mN / m and a contact angle of 140 °) using an Autopore IV 9500 device from Micromeritics.

The silica is subjected to a pressure treatment before the measurement. For this purpose, a Manual Hydraulic Press ( Order no. 15011 of Specac Ltd., River House, 97 Cray Avenue, Orpington, Kent BR5 4HE, UK ). In this case, in a "pellet die" with 13 mm inner diameter of Specac Ltd. Weighed in 250 mg of silica and loaded with 1 t as indicated. This load is held for 5 s and readjusted if necessary. The sample is then relaxed and dried for 4 h at 105 ± 2 ° C in a convection oven.

The silica is weighed into the penetrometer of type 10 to a precision of 0.001 g and, for a good reproducibility of the measurement, is chosen so that the stem volume used, ie the percentage Hg volume used to fill the penetrometer, is 20% to 40%. is. Subsequently, the penetrometer is slowly evacuated to 50 .mu.m Hg and left for 5 min at this pressure. The operation of the Autopore device is carried out according to the operating instructions with the software version IV 1.05. Each measurement is corrected by one empty measurement of the penetrometer. The measuring range is 0.0042-414 MPa.

Determination of the grindometer value

The determination of the grindometer value is carried out after DIN EN 21524 ,

Determination of the flowability

Angegeben wird das Messgefäß, bei dem das Pulver gerade noch ohne zu stocken ausfließt. Die nachfolgenden Beispiele dienen der Veranschaulichung der vorliegenden Erfindung, schränken diese jedoch in keiner Weise ein.The evaluation of the flowability takes place with glass outlet vessels of different outlet diameters. The evaluation is made with grades 1-7:

Indicated is the measuring vessel in which the powder just flows out without faltering. The following examples serve to illustrate the present invention, but do not limit it in any way.

Example 1: Lacquer with modified silicic acids

To be modified silica (Sipernat ^® 22, Sipernat ^® 50, Sipernat ^® 50S) is presented according to the weights in Table 1 each in a mixer (Somakon laboratory mixer) and start the mixing process (250 U / min, 25 ° C). The polymer used for the modification (polyethylene glycol 10,000 from Aldrich) is metered from aqueous solution (40% by weight) by slow dropwise addition (3 minutes). The mixing process is stopped after another 15 minutes. The particles remain free-flowing. Subsequently, a drying step (drying oven, 80 ° C, 24h) is performed. Finally, the particles are washed with an organic solvent (ethanol), filtered and dried again (vacuum drying oven, 80 mbar, 50 ° C, 24 h).

Table 1 lists the initial weights for the respective modifications of the silica types with polyethylene glycol 10,000. Sipernat ^® 22, Sipernat ^® 50 and Sipernat ^® 50S are silicas of Evonik Industries. Table 1: No. silica type Quantity [g] Polyethylene glycol 10,000 [g] Avg. Particle size d50 [μm] 1 Sipernat ^® 22 15 5 110 2 Sipernat ^® 50 15 5 40 3 Sipernat ^® 50S 15 5 16

4: 5 (mod Sipernat ^® 22: according to the invention fouling-reducing additive that by mixing the modified silicas 1-3 in a weight ratio of 6 is extracted from the listed in Table 1 modified silica types 1-3. Mod.Sipernat ^® 50: mod.Sipernat ^® 50S ) with a tumble mixer at 25 ° C, 30 min.

Thereafter, a paint is prepared according to Table 2 (composition paint). The first component is first prepared by means of a dissolver (Dispermat, diameter: 80 mm, 2000 rpm, 30 min). Table 2: substance Wt.% 1st component SILIKOPON ^® EF (Evonik Industries) 24.7 Sunscreen Tinuvin 292 (Ciba Specialty) 0.8 Deaerator TEGO ^® Airex 955 (Evonik Industries) 0.4 White pigment titanium dioxide Kronos 2315 (Kronos company) 19.9 Filler talc AT extra (Norwegian Talc) 1.5 butyl 3.9 Aerosil ^® R972 (Evonik Industries) 0.8 SILIKOPON ^® EF (Evonik Industries) 24.4 2nd component (additive + hardener) Fouling-reducing additive 11.4 DYNASYLAN® ^® AMEO (Evonik Industries) 12.2

In a second step, the hardener (DYNASYLAN ^® AMEO) and the anti-fouling additive are dispersed (Dispermat, diameter: 40mm, 1000rpm, 10min).

The paint is applied by means of a syringe (gun Sata Jet 90, inlet pressure 3 bar, 2 spray passes, nozzle diameter 1.4 mm) to the substrate to be coated. As a test surface roughened PVC plates are used (20 × 20cm for field trial, 7.5 × 2.5cm for laboratory test). After 8 hours, the coating according to the invention is cured and ready for use.

The sampling in the field trial was carried out under dynamic conditions (sample Karrussel with 8h rotation, 8h stoppage, about 5 knots) in the North Sea (Hooksiel). Subsequently, the evaluation was carried out by weighing, i. Determination of mass difference and comparison of surface growth. The paint system according to the invention containing the fouling-reducing additive reduces the fouling mass by more than 30% in comparison to the reference paint without the fouling-reducing additive according to the invention.

Example 2: Lacquer with a mixture of 3 silicic acids

From the quantities of silicic acid types given in Table 3, a fouling-reducing additive according to the invention is prepared. The mixture is carried out in a tumble mixer at 25 ° C, 30 min. Table 3: Weighers for silica mixture silica type Proportion (parts by weight) Mean particle size d50 (μm) Sipernat ^® 22 6 110 Sipernat ^® 50 4 40 Sipernat ^® 50S 5 16 Subsequently, as in Example 1, a lacquer is produced.

Results of field trials:

The field trial is carried out as in Example 1. The coating system according to the invention containing the fouling-reducing additive reduces the fouling mass by more than 40% compared to the reference coating without the fouling-reducing additive according to the invention.

Results of the laboratory experiments:

Laboratory experiments are performed to analyze the anti-fouling activity. The effectiveness of the formulations prepared in laboratory scale is tested in the specially developed experimental setup.

The marine bacterium Ps.atlantica is used as the test bacterium with marine medium (pH = 7.8; artificial seawater (eg marine broth supplied by Carl Roth).) The lacquer according to the invention is exposed to the colonization in the test medium (artificial seawater with test germ) for 24 hours Subsequently, the analysis of the surface growth of the lacquer according to the invention in comparison to the reference system without fouling additive by bacterial count or LifeDead-Staining by means of FilmTracer ^™ Live / Dead ^® Biofilm Viability Kit.With the paint system containing the fouling additive according to the invention (growth 57%) could In comparison with the paint without the fouling additive (fouling 100%), a reduction of microbial growth by> 40% can be detected.

Topography:

The surface topography of the prepared paint surface according to the invention is determined by means of a stylus instrument (Hommelwerke, Turbo roughness V6.14). Table 4 shows the measured roughness parameters for roughness profile Rt, Rz and average roughness Ra of the coating system according to the invention in comparison with a coating containing a mixture of two silicas (5 wt .-% Sipernat ^® 22 + 5 wt .-% Sipernat ^® 50), a Paint comprising a silica (5 wt .-% Sipernat ^® 22), and a paint without additive. Table 4: Lack without additive Paint with a silica Lacquer with two silicas Inventive paint system Rt [μm] 2.8 50,15 36.19 214.1 Rz [μm] 1.8 31.22 24.69 149.4 Ra [μm] 0.4 3.83 3.3 21.3

Example 3: Lacquer with a silica (comparative varnish)

A varnish as described in Example 1, except Sipernat ^® 820A (d50 = 7.5 micron) is used as an additive. Sipernat ^® 820A is an al-silicate from Evonik Industries.

Results of the laboratory experiments:

As indicated in Example 2, laboratory experiments are carried out. With the coating system containing the additive (Sipernat ^® 820A) (158% growth) (100% growth) found an increase in the microbial Aufwuchs by> 50% compared with the paint without fouling-reducing additive. The use of a silica is not suitable as a fouling additive.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2281855 A1 [0003]
• WO 9729157 A1 [0004]
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• JP 10025427 A [0004]
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• CN 101792534 A [0006]
• DE 102006030055 A1 [0007]
• EP 1591509 A1 [0009]
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• US 20080241408 A1 [0011]
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• EP 1398301 A2 [0025]
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Cited non-patent literature

• Development and Testing of Hierachically Wrinkled Coatings for Marine Antifouling, Efimenko, Applied Materials & Interfaces, Vol. 5, 1031-1040, 2009 [0014]
• DIN 53492 [0049]
• DIN 53601 [0064]
• DIN EN ISO 787-5 [0067]
• ISO 787-2 [0068]
• ISO 5794-1 / Annex D [0072]
• DIN-ISO 9277 [0072]
• DIN EN ISO 787-11 [0073]
• DIN 66133 [0074]
• Order no. 15011 from Specac Ltd., River House, 97 Cray Avenue, Orpington, Kent BR5 4HE, UK [0075]
• DIN EN 21524 [0077]

Claims (13)

Anti-fouling additive containing at least a) a modified or unmodified silica, silicate or silica gel having a mean particle size d 50 of 100-500 μm, b) a modified or unmodified silica, silicate or silica gel having an average particle size d50 of 20-70 microns and c) a modified or unmodified silica, silicate or silica gel having a mean particle size d 50 of <20 microns. Anti-fouling additive according to claim 1, characterized in that the mixing ratio of silicas, silicates or silica gels, based on the mass, a): b): c) 3: 2: 1 to 0.5: 0.5: 1. Anti-fouling additive according to claims 1 or 2, characterized in that a), b) and c) is a precipitated or fumed silica. Anti-fouling additive according to claim 3, characterized in that at least one precipitated or fumed silica is surface-modified. Anti-fouling additive according to claim 4, characterized in that the surface-modified, precipitated or fumed silica is surface-modified with a silane. Anti-fouling additive according to claim 3, characterized in that at least one precipitated or fumed silica is impregnated. Anti-fouling additive according to claim 6, characterized in that the impregnated, precipitated or fumed silica is impregnated with a polyethylene glycol. Process for the preparation of the growth-reducing additive according to claim 1, characterized in that a modified or unmodified silica, silicate or silica gel a) having a particle size of 100-500 μm, a modified or unmodified silica, silicate or silica gel b) with a particle size of 20-70 microns and a modified or unmodified silica, silicate or silica gel c) with a particle size of <20 microns mixes. Use of the anti-fouling additive according to claims 1-7 in coating systems. Use of the anti-fouling additive according to claim 9, characterized in that the coating system is a paint.  Lacquer, characterized in that this at least a) a modified or unmodified silica, silicate or silica gel having a mean particle size d 50 of 100-500 μm, b) a modified or unmodified silicic acid, silicate or silica gel having an average particle size d50 of 20-70 μm, and c) contains a modified or unmodified silica, silicate or silica gel with an average particle size d50 of <20 microns. Lacquer, characterized in that it contains the anti-fouling additive according to one of claims 1-7. A paint according to claim 12, characterized in that the mixture contains 2-30 wt .-% fouling additive.