Coating Material
The present invention relates to a coating material with a basic fluid in which body elements are dispersed.
In prior art it is known to produce coating materials, particularly in the field of paints and paint coats, in such a way that the same have properties which are optimized for the respective application. In this context, there may be mentioned for instance water steam transmitting, temperature or acid-resistant washable paints
Coating materials are known from prior art, for example on the basis of acrylic resins which contain glass and/or ceramic particles for improving the scratch resistance, thermal conductivity, mechanical stability under load or chemical resistance, The particles have a size in the micrometer range. There are used for instance glass micro bubbles as the same are disclosed in the document US 4, 767,726 of Minnesota Mining and Manufacuring Company
The applicant's products TC-Texx and TC-Well represent such coating materials. These coatings are solvent-free composite materials in which microscopically small ceramic bubbles are embedded in preferably elastic ana breathable dispersions. Due to the ceramic bubbles, the coatings exhibit a high chemical resistance, high mechanical stability under load, longevity, a high cracking and brittle resistance as well as excellent thermal properties. Normally it may be assumed that due to their properties the addition of ceramic bubbles to wall paints makes it possible to create specical effects, whereby in addition to an increased scratching resistance and

improved non-sticking properties an increase in the quality is obtained for paints, coatings and other building materials. Due to the size of the ceramic bubbles in the micrometer range these coatings particularly have a very low tendency to soiling.
In addition to the above-described coating materials there are known from prior art coating materials, of which the surfaces exhibit the so-called ..Lotus effect" These materials develop surface layers with nanoscale structures Due to the nanoscale surface dirt and water cannot adhere to this surface and drip off.
Disadvantageous^, said Lotus effect of a paint coat is preserved only as long as the nanoscale structure of the paint coat surface is intact. If the layer of the coating which supports this structure becomes destroyed for instance through environmental influences of an arbitrary kind or through mechanical influences, the paint coat will no longer exhibit any Lotus effect. Especially a spot-like disturbance of the nanoscaie surface will lead to a particularly anaesthetic soiling of the painted surface, whereas nondisturoed surface regions continue looking new,
Starting from the above-described prior art the invention is based on the p r o b I e m of providing a coating material having properties which are improved compared
to those of the known materials.
This problem is solved by a coating material with a basic fluid in which body elements are dispersed and which is characterized in that the surface of the body elements carries nanoparticles.
Objects and surfaces which are provided with the coating material according to the invention, for instance facades of buildings, roofs and wails, both in the interior and exterior areas, will permanently stay clean or get dirty only very slightly. Dirt particles landing on the treated surfaces and objects lie there only loosely and are washed off under the influence of airflows or water.
Preferably, said nanoparticles are arranged on the surface of the body elements In such a manner that the same exhibit the so-called Lotus effect To this end, the nanoparticles are specifically oriented, so that the structure of the surface can be specifically produced or influenced. Advantageously, surfaces which are treated on

the basis of the nanotechnology are not sealed with a closed layer, but instead remain open for the diffusion of vapour and remain transparent, whereas water, dirt particles, microbes and radiation of high energy, for instance in the range of 500 nm to 2500 nm, do not reach the actual surface. The energy of solar light in the wave length range of 500 nm to 2500 nm is introduced in the surface only strongly reduced (UD to 20% at maximum), so that the actual coating material warms up only slightly, in this way, tensile stresses are avoided or considerably reduced, whereby the durability of the coatings, especially in the area of roof surfaces and facades, is considerably improved. In addition, the heating up of buildings which are coated with the coating material according to the invention is reduced to a large extent.
The body elements are preferably ceramic body elements which may be cristalline and/or polycristailine body elements. It is also conceivable to use glass-like body elements as body elements. Said body elements may have an arbitrary shape, but spherical bodies are preferred because of their small surface. When hollow balls (buobles) are used, the same advantageously have a low weight. The body elements have sizes in the micrometer range.
According to a particularly preferred embodiment of the invention the body elements are micro bubbles. These glass micro bubbles have with respect to their weight a composition for instance which substantially consists of 70 to 80% SiO2, 8 to 15% CaO, 3 to 8% NaO2 and 2 to 6% B2O3 and about 0-2 to 1 5% SO3, the CaO:Na20 ratio being from 1 to 1.3, The SQ3 here forms the blowing agent required for the produtton of these glass micro bubbles. The document US 4,767,726 describes further additives for changing or improving the properties of the glass micro bubbles in dependence of their intended use. From the documents US 3,365,315 and 5,064,784 methods for the production of glass micro bubbles are known which comprise high temperature melting of glass and blowing-off in the form of particles while being foamed with a blowing or expanding agent. The document EP 0 601 594 B1 describes a method of producing particularly cristalline micro bubbles which are used among others also as fillers in paints or refractory materials, in order to meet different requirements. Depending on the intended use, the micro bubbles may be cristalline and/or polycristailine micro bubbles, ceramic micro bubbles or glass micro bubbles. In the coating material according to the

invention micro bubbles as those described in the above-mentioned prior art are preferably used.
The surface of the body elements is filled with nanoparticles. According to a
particularly preferred embodiment of the invention the same have a mean diameter
of less than 200 nm, preferably less than 100 nm and more preferably less than 50
nm. Preferably, the nanoparticles are nanoscale particles of the group consisting of
aluminiumoxides, aluminiumoxydehydrates, titaniumdioxides and
zirconlumdioxides Further it is possible that the nanoparticles are nanoscale oxides of the elements of the group consisting of aluminium, titanium, zirconium, tantalum and tin, which nanoscale oxides can be prepared from brine solutions. It is described as advantageous to use also surface-modified particles or for instance to effect a surface modification after the de-agglomeration, since these are effective to achieve a stabilisation against a re-agglomeration
The body elements carrying nanoparticles are preferably placed in an organic, inorganic or organic-inorganic matrix, particularly on the basis of acrylic resins Acrylic resins are normally used as solutions in organic solvents or as aqueous dispersions, for instance for interior and exterior paint coats or for varnishing paper, wood, metal and other materials The body elements carrying nanoparticles are present in the matrix in a finely dispersed form.
If the coating according to the invention is applied to a surface as a paint coat, a ceramic surface is developed which is formed from the body elements carrying nanoparticles. By the selection of a suitable body element-forming material numerous properties of the coating such as the tendency to brittleness, vapour permeability, behaviour in fire, bonding strength, thermal insulation and the like can be determined Due to the nanoparticles there arranged, the surface of the body elements is nario-structured, for which reason dirt particles, water and the like cannot adhere to it. The surface of the coating is composed of nano-structured surface areas of the rim-side body elements of the coating. Accordingly, the entire surface of the coating includes like the body elements a nano-structured surface, for which reason dirt, water and the like cannot adhere and the surface is substantially self-cleaning

Since not only the surface itself of the coating is nano-structured, but the surface of the body elements, their properties like hardness, stability, mutual bonding strength and so on are adjustable, the serive life of the coating according to the invention is much longer than that of conventional coatings with Lotus effect, since the structure of the coating successfully resists to various influences like temperature changes, rain, frost, impact and the like.
Further details and features of the invention will become apparent from the following description of an exemplary and not limiting preferred embodiment of the invention with reference to the attached drawing figure
Figure 1 shows a schematic section through a surface 2, taken transversely to the surface 2, which is provided with a coating 1 according to the invention, The coating 2 has a matrix 3 The matrix 3 is elastic and breathable. The matrix has embedded therein ceramic micro bubbles, hereinafter referred to as bubbles 4. The bubbles 4 are microscopically small, ultra-lightweight hollow ceramic balls which form about 50% of the constituents of the coating. On a coating area of approximately 1 m2 round 600 millions of these bubbles 4 are arranged Due to the fact that the elastic matrix 3 is interrupted by the bubbles 4, the coating 1 itself has a very low thermal expansion coefficient and a high resistance to temperature changes By an appropriate selection of the matrix 3 and due to the fact that the bubbles 4 are ceramic elements, the coating exhibits a high resistance to acids, salts and their solutions, whereby it is highly resistant to environmental influences. if ceramics on the basis of silica are selected as a material for the bubbles 4, the coating s given a nigh resistance to mechanical influences on the surface. The bubbles 4 are either tilled with air or have a vacuum in the interior thereof. Accordingly, they have a small mass and a low thermal conductvity.
The surface of the bubbles 4 carries nanoscale particles, of which the size is smaller than that of the bubbles 4 by a factor between 100 and 10000 On the surface of the bubbles 4 the nanopartides form in the known manner a structure which is required for obtaining the Lotus effect.

List of reference numbers
1 surface
2 coating
3 matrix
4 bubbles

Pate nt C I a i m s
1. Coating material with a basic fluid in which body elements are dispersed,
characterized in that the surface of the body elements is filled with
nanoparticles
2. Coating material according to claim 1, characterized in that the body elements
are ceramic tody elements.
3. Coating material according to claim 1 or 2, characterized in that the body
elements are cnstalline body elements.
4. Coating material according to one of the preceding claims, characterized in
that the body elements are poiycristalline body elements.
5. Coating material according to one of the preceding claims, characterized in
that the body elements are glass-like body elements.
6 Coating material according to one of the preceding claims, characterized in that the body elements substantially consist of sodium borosilicate glass.
7. Coating material according to one of the preceding claims, characterized in
that the body elements are micro bubbles.
8. Coating material according to one of the preceding claims, characterized in
that the nanoparticles have a mean diameter of less than 200 nm, preferably
less than 100 nm and particularly preferred less than 50 nrn.
9 Coating material according to one of the preceding claims, characterized in that the nanoparticies are nanoscale particles of the group consisting of aluminiumoxides, aluminiumoxydehydrates, titaniumdioxides and zirconiumdioxides.

10. Coating material according to one of the claims 1 to 8, characterized in that the nanoparticles are nanoscale oxides of the elements of the group consisting of aluminium, titanium, zirconium, tantalum and tin.
11 Coating material according to one of the preceding claims, characterized in that the body elements filled with nanoparticles are introduced in a solution on the basis of acrylic resin.
12. Coating material according to one of the preceding claims, characterized in thai the nanoparticles are arranged on the surface of the body elements in such a way that the Lotus effect is produced.