BG97439A - Solid substance particles on oxide basis, covered by ceramic coloured bodies, method for their preparation and application - Google Patents

Abstract

Particles of solid, in particular corundum, are particularly suitable for coloring, wear-reducing and / or slip-reducing additives for ceramic glazes, for example for ceramic floor tiles.

Description

Ceramic colored bodies oxide-based solid particles, process for their preparation and application thereof, the invention relates to oxide-based solid particles, in particular corundum, which are coated with ceramic colored bodies. The invention also relates to the use of these particles as colorants, abrasion reducing agents and build-up components, in particular in ceramic glazes, enamel, paint and coatings. those.

oa the improvement of mechanical properties, in particular wear resistance and slip safety, often entrained solid particles in heavily loaded surfaces. Examples of such surfaces are, inter alia, ceramic flooring, respectively, their glazes, in particular for floors in wet rooms, such as public or private bathrooms, or outdoors, or flooring made of other materials such as plastics or artificial stones, which are exposed to the same loads Jat particles of solid, substances for this purpose are used above all all corundum fractions, which, unlike non-oxide solids, such as solids or silicon carbide, can be introduced into glazes and enamel, the danger of interfering chemical reactions; and at bargain prices they have a behind

tensile strength and abrasion resistance.

The disadvantage of the usual factions of corundum is that it is them. only limited colorings and joints are possible to obtain surface surfaces, which results in restrictions on their use in residential construction and in the construction of public buildings. The reason for. this is due to the properties of those corundum fractions, which are colored white to brown or gray to blue, respectively for special types of corundum from pink to ruby and may change when used in ceramic glazes during the baking process , satisfactory results can therefore only be achieved when the glaze has approximately the same color, which significantly narrows the color palette and, of course, excludes all intense color tones. above normal value does not eliminate this disadvantage, since the corundum particles according to their purpose must be located on the surface of the glaze, and on the other hand, this leads to a significant increase in cost. possibly the means of forming a water pole? nectar, such as sprays of different colors between gl; zuras and solids.

it is therefore an object of the present invention to make available oxide solid particles which can be introduced into any colored glazes and other surfaces without impairing the color effect and which allow the color palette to be expanded to obtain uniform colors and special means for surface effects such as spraying, matting, melting, marbling, and other specimens.

This object is accomplished according to the invention by using oxy-based solid particles coated with ceramic colored bodies containing at least a ceramic colored body and at least one bonding agent.

It has been found that oxide-based solids may be coated with one or more ceramic colored bodies and a bonding agent.

but in this way the good mechanical properties of the solid particles can be utilized, without, however, being limited in coloring or reducing the number of possible means of obtaining effects in those objects in which the particles find application.

Ceramic colored bodies are to be understood here as derived from (inorganic) oxides during the firing process, inorganic compounds / eg rutile, spinel, chromite, aluminates, ferrites, etc. similar /, which are used as a coloring component in ceramic glazes and characterized in that they do not dissolve or only slightly dissolve in ceramic glazes.

in addition, depending on the application-specific requirements, it is also possible to use inorganic pigments such as single-phase or multiphase metal complexes, metal powders, etc., as well as staining trites.

Review has been made in napoimer ^{in · R ° m PP »Chemie -Lexikon} ,

9. Auflage, Band 4, 1991, G. Thieme Verlag Stittgart; W. Heinz, Si1icat-Lexikon, 1st Auflage 1 985, Akademie-Verlag Berlin, S. 226

It is common knowledge that surfaces that are not exposed to temperatures above 300 ° C, such as paints or varnishes, surfaces of plastics and concrete, can be used seamlessly with all ceramic colored bodies within the meaning of the above definition. Glasses specifically in tile glazes mix melted colored glass with the glaze around the core of the solid, which can lead in part to a desired melting effect.

When using inorganic pigments in glazes, in each case, it must be attempted to determine whether there is a neutral behavior of inorganic pigments in the glaze firing.

As the base material of the invention for the coated solid particles on an oxide base, aluminum oxide, zirconium oxide, silica, spinels or mixtures thereof, optionally together with conventional impurities and / or additives such as stabilizers or auxiliaries, are used for sintering.

Particularly preferred material is corundum, in particular fused or sintered corundum.

The particle size of the solids coated according to the invention ranges from 0.03 to · 3 mm, but preferably 0.06 'to 0.5 mm. Particularly preferred are narrow strips of fractions as described in FEPA- standard 42-D -1984, respectively, in 43-D -1984.

because of their size, the coated solids particles can be very well processed as they are loose and free of dust and therefore do not agglomerate.

They are therefore applicable both to the dry glazing method and to the conventional wet glazing method and can be well tolerated and dispensed by automatic means.

The ceramic colored body is used in an amount of 2 to 20% by weight, preferably from 5 to 10% by weight, relative to the amount of particles before coating. The amount to be coated depends on the grain size of the colored body, the desired color intensity, the depth of staining as well as the particle size of the solid.

when using fine particle size fractions (for example P 220 according to FEPA), the keoamic glazes can thus be colored,

to give the impression of a homogeneous visual coloration. as is usual; colored; of icing through the addition of colored bodies.

However, when using the coated solids particles, a substantially smaller amount of colored bodies is sufficient to achieve the same color saturation. as with the usual glaze coloring. such as, for example, a chase additive of 7 weighted colored coats, particles of corundum having a colored body content of up to 10 weight%, i.e. a maximum of 0.7% by weight of colored bodies, relative to the total dry glaze mixture, achieves the same color saturation as with the direct addition of 5% by weight of colored bodies to the same glaze.

but this makes it possible to drastically reduce the proportion of heavy metals in the glaze without having to change other components of the colored body.

As a coating binder, it is generally suitable for any binder that sufficiently moistens both the solid and the colored body to form a sufficiently rigid adhesive layer and not interfere with the intended use of the coated particles, for example, when baking glazes. on tiles.

preferred binders are silicic acids, salts of silicic acids, respectively, with or without the addition of discolored glazes, aluminum monsyrosphate or mixtures of these substances. Alkali silicates are particularly preferred. (water glass), such as sodium hydroxide glass.

coated solids particles according to the invention can be obtained in a simple and advantageous manner. For this purpose, for example, the solids particles to be coated are wetted most with a solution or suspension of a binder <

6 · · · · · · · · · · · · · · · · ·

This can be accomplished, for example, by further mixing in a conventional mixer or by spraying a moving particle, patho-solution or suspension, preferably using a solution or suspension with water or other easily volatile liquid. - more solution, respectively, a suspension of binder than necessary for uniform wetting of the particles and binding of the intended amount of colored body. The amount required depends on the specific surface, resp. tively the size of the particles and the viscosity of the solution, respectively of the suspension and the colored bodies.

1when the wetted particles are then mixed substantially with the required amount of the fine sprayed solid to form a uniform coating layer.5a, preferably, the quantitative ratios between the binder and the colored bodies are selected in such a way that there is no excess of this coating layer unnecessary binder because otherwise the particles stick together easily and form agglomerates. After applying the colored body, the particles first dry. Further thermal treatment depends very strongly of the desired application and covers a temperature range of

at least 30 ° C for use on surfaces of plastics, concrete, and especially for use with colored glazes of different types of corundum in tiles to achieve an escapement, and up to

-maximum 1200 ° C when used in tiles when absolutely inert behavior of the layered coound is required.

finally, agglomeration and / or sieving is finally carried out to destroy the resulting agglomerate and / or suture to be removed.

A preferred application of the coated solid particles according to the invention is their addition to ceramic glazes

D1 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Enamel or enamel. to reduce the surface and thus reduce the risk of slipping. The particles are preferably introduced into the surface of the glaze, respectively, into the enamel layer. This can be done by pouring into the already applied slurry or powder form. of glaze or enamel respectively before baking or during the baking process.In addition, the addition of particles it can be used to influence the appearance of the finished coating of glaze or enamel, for example to achieve an etching of matting by changing the structure of the surface, or to obtain sprays or other similar colored ejections when on the weight of the glaze, respectively enamel and particle coating are different colors, tones and / or color intensities.

e in these cases, depending on the degree of transparency of the glaze, or the enamel, respectively, it may be advantageous to distribute the particles evenly in the glaze mass or. gently applying the so-called underglaze colors first to the substrate and then covering with the glaze.

Particularly preferred is the application of the coated solids particles in the glazes of ceramic floor tiles for outdoor use, in wet rooms and for highly worn floor coverings, in particular in public buildings and in industry.

another preferred application of the coated solid particles according to the invention is their addition to plastics and masses for the preparation of coatings, for example for floor and wall coverings. 1when their advantages are also shown, namely the bonding of the wear-resistant and color layout.

Cb.jq so preferred use of coated according to • ·

the invention particulate matter is their addition to paint materials for mechanically loaded painted surfaces.

in addition, the particulate matter coated according to the invention is used, for example, as an adjunct to masses, for the production of artificial stones, oetons or plasters.

The following examples should further clarify the scope of the present invention.

Example 1:

To 1 kg of corundum / white electrocorundum, particle size distribution

P-120, N-O-110 µm / 25 ml of a mixture of 60% by volume sodium hydroxide glass / 34.2 wt% solids content, S wt. %

At ₂ 0,

26.6 wt.% & 0 ₂ , viscosity about 70 mPa.sec / and 40 volume% water and mixed for about 20 minutes using a paddle mixer.

100 g of a solid, e.g. spinel type (grain size 100% less than 63 µm) is added uniformly to the corundum, and the mixing process is continued for another 20 minutes. The obtained corundum coated particles are dried at 150 ° C. residual humidity of maximum 0,1% / in a tumble dryer for 4 hours with circulating air /. After drying, a screening at 212 μm is carried out. Then the dried particles except the coarse fraction are baked at 1000 ° in an oxidizing atmosphere / air. / in a rotary kiln stay belt is 2 hours.

After cooling, the particles were disaggregated on a vibrating sieve using solid rubber balls and sieved at 212 µm to separate the remaining agglomerates. The product is a granular granular fraction that creates an optical fraction. homogeneous coloring.

Example 2:

Analogous to Example 1, fractions of corundum with always 10 wt.% Colored body were covered.

these colors and compositions / in weight //: green: C ^r 2 0 3 9 5% A1 ₂ 0 ₃ 3% S and 0 ₂ 2% brown: ZnO 50% ^Fe 2 ° 3 25% ^Cr 2 ° 3 25% blue: C ° C ° 4 20% A1 ₂ 0 ₃ 80% yellow: ^P 3 ° 4 40% ^Sat 2 ° 3 4 0% ZnO 10% CaO 10% The following table shows what is possible in conjunction with the ordinary J.

coloring glaze reduction of the content of the key in conjunction _O zka with environmental compounds in the glaze / in weight by the use according izoboetenieto particles tvaodo substance • · • · · · · ·

color Important for environmental protection compound on direct staining with 5% by weight colored body / wt. % / * / When stained is with 7% by weight of the particles according to the invention / wt. % / oiled With ^r 2 θ 3 4.75 0, o7 Brown ΖηΟ 2.50 0.35 Cr _? 0 1,25 0.18 Blue ^From 3 ° 4 1.00 0.14 shit ^P 3 ° 4 2.00 0.28 Sb 2 ° C 2.00 0.28 ΖηΟ 0.50 0.07

* / The difference of up to 5% is the constituent components of the colored body, which are not themselves important

Al St Ogr? ^is - £ ^ h · · / of the environment / for example

Claims (12)

PATHWh ill · ώ 'shgu / th! 1.4 oxide-based solid asics characterized in that they have a sheath containing at least one ceramic colored body and at least one binder. Coated solid particles according to claim 1, characterized in that the base material is composed of the group of aluminum oxide, zirconium oxide, silicon oxide, spinels and mixtures of these oxides. 3. coated solid particles according to claim 2, characterized in that the base material is corundum. Solid particles according to one of claims 1 to 3, characterized in that the particle size ranges from 0.03 to 3 mm. Uncoated solid particles according to one or more of the claims 1 to 4, characterized in that the amount of ceramic colored bodies in the shell is 5 to 10 parts by weight relative to the coated particles. _w o .Cover solid particles according to one or several of claims 1 to 5, paoakterizirashi in that the binder consists of silicic acid, silicic acid, colorless glaze frit and aluminum orosfat or mixtures of these substances . 7 coated solid particles according to claim 6, characterized in that the binder is an alkaline silicate. A process for producing coated solid particles according to one or more of claims 1 to 7, characterized in that the particles to be coated are wetted with a solution or suspension of the binder and then mixed with the required an amount of finely sprayed colored body is dried. -12 • · · · The method according to claim 6, characterized in that an aqueous alkaline silicate solution is used as the binder solution. Step 10 according to claim 8 or 9, characterized in that the coating layer of the solid particle after drying at a temperature of from 300 to 1200 ° C is cured, respectively, fixed by firing. Application of coated solids according to one or more of claims 1 to 7. as an additive to ceramic glazes D ·. or email. Use according to latent claim 11 as a wear-reducing additive and / or slip protection in the glazing surface of ceramic tiles, in particular floor tiles. Use of the coated solid particles according to one or more of claims 1 to 7 as an admixture for plastics or coating masses. Use of the coated solid particles according to one or more of claims 1 to 7 as an adjunct to paint and varnish materials. Application of the coated solid particles according to one or more of claims 1 to 7 as admixture to concrete, artificial stones or plaster.