WO2019141502A1

WO2019141502A1 - Dispersion paint

Info

Publication number: WO2019141502A1
Application number: PCT/EP2019/000006
Authority: WO
Inventors: Wolfgang Dilla; Christoph Nover; Ralf-Dieter Schnebeck; Thomas Steinbrecher; Marijan Vucak
Original assignee: Schaefer Kalk Gmbh & Co. Kg
Priority date: 2018-01-16
Filing date: 2019-01-10
Publication date: 2019-07-25
Also published as: EP3740538A1

Abstract

The invention relates to dispersion paint, which comprises at least water and calcium carbonate particles, the calcium carbonate particles having been obtained by spray-drying a precipitated-calcium carbonate particle suspension. The dispersion paint is particularly suitable as wall paint for interior and exterior use.

Description

emulsion paint

The present invention relates to an emulsion paint comprising at least water and spray-dried calcium carbonate particles. preferred

Fields of application of the emulsion paint include in particular their use as wall paint for the interior and the exterior (facade paint).

Emulsion paints, in particular plastic dispersion paints, are one

Collective term for paints based on dispersions, in particular polymer dispersions (plastic, synthetic resin dispersions) and colorants, in particular pigments. The emulsion paints are often referred to as latex paints or summarily as binder colors.

According to DIN 55 945 (12/1988), a paint is defined as "liquid to paste-like coating material, which is applied primarily by brushing or rolling". The paints give after the order on a

Substrate after physical and / or chemical drying a solid coat.

Spray-drying of colorants and pigments, such as acid or azo dyes, basic dyes, dispersing dyes,

Reactive dyes, dye intermediates, corresponding fillers,

Barium sulfate, cadmium carbonate, cadmium sulfite, calcium carbonate, ceramic dyes, iron oxide, kaolin, lithopone, phthalocyanines, titanium dioxide and

Zinc chromates, is already known.

For example, US 2010/0263576 A1 discloses a dry, aggregated

Calcium carbonate comprising calcium carbonate and at least one inorganic binder, the dry calcium carbonate aggregating a middle one

Particle size (D50) of at least 5 pm. A composition containing such a calcium carbonate is also described. Further, a product such as a paint and methods for producing a product containing such an aggregated calcium carbonate are shown. As calcium carbonate both ground calcium carbonate (GCC) and precipitated calcium carbonate (PCC) can be used.

The preparation of the aggregated calcium carbonate may optionally after a

Procedures are carried out which u.a. the spray-drying of a

Calcium carbonate suspension. However, in this context, the spray-drying of a suspension of precipitated calcium carbonate particles is not mentioned.

Preferred amount ranges for the inorganic binder are not mentioned.

In the examples of US 2010/0263576 A1, the spray drying

various mixtures of ground calcium carbonate having an average particle size of about 0.8 pm, inorganic binder

(Ammonium borate, sodium borate, sodium silicate, boric acid or phosphoric acid) and water. The resulting aggregated calcium carbonates are tested in paints having a pigment volume concentration (PVK) of 65% or 45%. The comparative materials used are fine GCC, fine spray-dried GCC with an average particle size of 0.7 μm and coarse-grained GCC with an average particle size of 12 to 14 μm.

The weight fraction of the binder, based on GCC, is between 2.4% by weight and 9.1% by weight for the aggregated calcium carbonates.

For the coarse grained GCC, a sheen (gloss at 85 °) of 2.0 (PVK 65%, Table I), 4.8 (PVK 65%, Table I) or 7.2 (PVK 45%, Table III) as well as an opacity (contrast ratio KV) of 94.53 (PVK 65%; Table I), 97.09 (PVK 65%; Table II) or 95.52 (PVK 45%; Table III).

For the fine GCC, a sheen of 19.0 (PVK 45%, Table III) and an opacity of 95.50 (PVK 45%, Table III) are reported.

For the fine spray-dried GCC, a sheen of 39.3 (PVK 65%, Table I) or 19.8 (PVK 45%, Table III) and an opacity of 97.80 (PVK 65%, Table I) or 95, 34 (PVK 45%, Table III). For the dry, aggregated calcium carbonate, Sheen values are 1.5 to 3.8 (PVK 65%, Table I), 2.0 to 25.7 (PVK 65%, Table II), or 3.4 to 6.4 (PVK 45%, Table III) and an opacity of 97.34 to 98.24 (PVK 65%, Table I), 97.28 to 98.82 (PVK 65%, Table II) or 95.06 to 95, 39 (PVK 45%, Table III).

Values for abrasiveness and wet abrasion can not be found in the document.

Basically, all inorganic binders of US 2010/0263576 A1 are classified as hazardous to health and therefore their use is always problematic. So there is a health risk in the production of aggregrierten calcium carbonate, in the production of colors under

Use of the aggregated calcium carbonate, in the processing of paint and in the renovation of paints obtained using such a paint, as this may result in harmful dust that can be inhaled, and as renovation waste may be generated during disposal and / or or combustion can be hazardous to health. The use and handling of inorganic binders therefore requires special safety precautions, the attention of which raises the price of any potential use of inorganic binders.

Apart from that, inorganic binders per se are comparatively expensive and price-driving for every application. Against this background, therefore, the use of inorganic binders in the production of

Dispersion colors are avoided as possible.

A further disadvantage is the comparatively high titanium dioxide content of

Paints of this pamphlet (65% PVK painting color: 4.9%; 45% PVK painting color: 9.5%). Due to the high cost of titanium dioxide will be

Paints with at least comparable properties and the lowest possible levels of titanium dioxide desired.

WO 2014/202836 A1 relates to a composition containing precipitated

Calcium carbonate, process for the preparation of the composition as well

Applications of the composition. The composition comprises a plurality of necessarily spherical granules having an average particle diameter of 1 to 50 μmh, which are formed from precipitated primary calcium carbonate particles having a particle size of 30 to 60 nm, wherein at least a portion of the primary particles can be released by deagglomeration in aqueous suspension. The composition can for

Modification of binders of paints, printing inks, plastics, adhesives, sealants, surface finishes and

Pulp sizing agents are used. The document further relates to a method for storing precipitated calcium carbonate particles with a mean diameter in the nanometer range.

The preparation of the calcium carbonate primary particles is preferably carried out by spray drying.

The focus of the document is on paper applications in general.

Emulsion paints, in particular wall paints, are not described in the document.

Furthermore, neither Sheen values nor values for the abrasiveness or the wet abrasion of the document can be found.

US 3,992,314 teaches a method for producing a granular,

Calcium carbonate-containing mixture in which the calcium carbonate particles have a high effective surface and a low degree of agglomeration. The process consists essentially of the following steps that one:

a. water soluble alkali carbonates, bicarbonates and / or sesquicarbonates mixed with water and submicron calcium carbonate particles, wherein the weight ratio of the alkali metal salt to the calcium carbonate is from about 1: 2 to about 75: 1 to form an aqueous slurry that is substantially free of water-soluble silicate, phosphate and anionic surfactant salts; and

b. the slurry from step a. spray-dried to form the granules containing calcium carbonate.

The median diameter of the submicron calcium carbonate should preferably be in the range of about 0.01 to about 0.5 pm.

The aim of the document is the use of calcium carbonate particles as crystallization seeds in combination with a precipitating builder to accelerate the removal of soluble calcium ions from wash water. Emulsion paints, in particular wall paints, are not mentioned in the document. Likewise, there is no information on Sheen values and abrasiveness or wet abrasion.

The publication by V. Vergaro et al., "Synthesis of calcium carbonate nanocrystals and their potential application as vessels for drug delivery" AIP Conference Proceedings 1667, 020014 (2015); doi: 10.1063 / 1.-4922570 describes the preparation of pure and stable calcium carbonate nanocrystals by spray-drying and the use of calcium carbonate nanocrystals in pharmacotherapy. Emulsion paints, in particular

Wall paint, are not mentioned in the document. Likewise, there is no information on Sheen values and abrasiveness or wet abrasion.

EP 2 796 412 A1 describes a process for the preparation of nanoscale calcium carbonate particles by spray drying, comprising the steps of

1) an aqueous solution of sodium bicarbonate with an aqueous

Solution of calcium chloride mixes and

2) atomizing the mixture in a preheated air stream to thereby obtain calcium carbonate powder and sodium chloride.

The resulting calcium carbonate comprises nanoparticles smaller than 200 nm, in particular nanorods with a length of about 100 nm and a width of about 50 nm.

The reference teaches that calcium carbonate is often used in the manufacture of plastics, rubbers, adhesives, sealants, papers, inks, wraps, paints, cosmetics and pharmaceuticals. By modifying the surface of the calcium carbonate nanoparticles, it would be possible to control the theological and mechanical properties of the material. Furthermore, in plastic materials, the nanoscale calcium carbonate can be used as a pigment and replace up to 25% of the commonly used pigments.

Emulsion paints, in particular wall paints, are not mentioned in the document. Likewise, there is no information on Sheen values and abrasiveness or wet abrasion. WO 2013/050495 A1 relates to precipitated calcium carbonate particles in the form of nanofibers or chain-like agglomerates. Furthermore, the concerns

Reference Paints, papers and paper coatings comprising the precipitated calcium carbonate particles.

Spray drying is mentioned as one of several ways of drying the precipitated calcium carbonate particles (see page 10, lines 3-9).

Exemplary aqueous emulsion paints include 5.0 or 6.0 weight percent titanium dioxide and 15.0 weight percent or 6 weight percent to 14 weight percent PCC (see page 13, Table).

The aim is to produce watery, matt or silky-glossy paints

(so-called middle sheen).

Furthermore, the publication contains information on the abrasiveness (see page 14, lines 30 to 33, Tables 1-4). It is noticeable, however, that the "inventive" examples of this publication have a better opacity, but a poorer sheen and usually also a worse abrasiveness.

The publication M. Vucak, K. Hölzer. H. Stöver "Optimum Coverage" Paint & Varnish, 05/2005, page 34 describes the use of precipitated material

Calcium carbonate in the formulation of matt interior emulsion paints. In the tested formulations, a pigment volume concentration (PVK) of 80% and a solids content of 62% by weight were selected. The test formulation comprised 4.0% by weight of titanium dioxide, 36.8% by weight of GCC (dso = 5 pm); 15.0% by weight of PCC, 10.4% by weight of vinyl acetate-ethylene dispersion (53%), 33% by weight of water and additives (thickener, dispersant, preservative, pH regulator,

Defoamer, wetting agent). The contrast ratio (KV, the values are between 97.0% and 98.9%), the whiteness Ry (the stated values are between 91, 4% and 94.1%) and the wet resistance (the stated values) were investigated between 50.4 g / m ² and 79.9 g / m ² ) and the sheen (the values stated are between 4% and 9%).

Against this background, better dispersion paints were desired according to the invention, which are particularly suitable as wall paint for indoor and outdoor use. The paint obtained by application of the emulsion paint should have the lowest possible sheen. Furthermore, the should Coatings obtainable by application of the emulsion paint have high whiteness and high hiding power. Furthermore, the wet abrasion of by

As low as possible to the applications of the emulsion paint available paint.

Finally, a possible cost-effective solution was sought.

In particular, the use of expensive ingredients, such as titanium dioxide as a pigment, should be reduced as significantly as possible.

These as well as additional tasks arising from the described

Associations necessarily result, were solved by the provision of an emulsion paint according to claim 1. Preferred embodiments of the dispersion paint of the invention are in the claim 1

described dependent claims. Furthermore, particularly preferred fields of application of the emulsion paint according to the invention are put under protection.

By providing an emulsion paint comprising at least water and spray-dried calcium carbonate particles, which is characterized in that the calcium carbonate particles were obtained by spray-drying a suspension of precipitated calcium carbonate particles, it is surprisingly possible to obtain a better one Disperse paint accessible, which is particularly suitable as a wall paint for indoor and outdoor use. The available from orders of the emulsion paint

Painting has a comparatively low sheen. Furthermore, the paint obtainable by applying the emulsion paint has high whiteness and high hiding power. In addition, the abrasiveness and wet abrasion of the paint obtainable by applying the emulsion paint is very low.

Finally, a very cost-effective solution is shown, in particular the use of expensive ingredients, such as

Titanium dioxide as a pigment, significantly reduced

The subject of the present invention is accordingly a

Emulsion paint, comprising at least water and spray-dried

Calcium carbonate particles.

The water contained in the dispersion paint according to the invention preferably serves as a solvent or dispersant for in the

Disperse color contained ingredients, especially for the

spray-dried calcium carbonate particles. The water content of Emulsion paint is preferably at least 10.0 wt .-%, preferably at least 20.0 wt.%, Particularly preferably at least 30.0 wt .-%, advantageously at least 35.0 wt .-%, in particular at least 50.0 wt. %. In each case based on the total weight of the emulsion paint.

Other solvents and / or dispersants may be added to the dispersion paint of the invention as needed. The content of these other solvents and / or dispersants in the emulsion paint can basically be chosen freely. According to a first preferred

Embodiment of the present invention, it is preferably in the range of 1, 0 wt .-% to 20.0 wt .-%, in particular 3.0 wt .-% to 15.0 wt .-%, each based on the total weight of the emulsion paint , Within the scope of a further preferred embodiment of the present invention, the content of further solvents and / or dispersants in the emulsion paint is less than 5.0% by weight, preferably less than 2.5% by weight, more preferably less than 1.0% by weight. %, suitably less than 0.5 wt .-%, in particular less than 0.1 wt .-%. According to a very particularly preferred embodiment of the present invention, the emulsion paint contains no further solvents and / or dispersants.

The dispersion paint according to the invention expediently contains at least one binder, preferably at least one organic binder and / or at least one inorganic binder, in particular at least one organic binder. "Binder" in the context of the present invention refers to products which combine the same or different materials. The setting is preferably carried out by physically drying the emulsion paint. Organic binders refer to the

present invention, all binders from the group of organic

Compounds and inorganic binders in the context of the present invention are all binders from the group of inorganic compounds. Organic compounds in turn refer to all

Compounds of carbon other than hydrogen-free

Chalcogenides (e.g., CO, CO2, CS2) and their derivatives (e.g., H2CO3, KSCN), salt and metallic carbides, and metal carbonyls. The inorganic compounds include besides the hydrogen-free ones

Chalcogenides (eg CO, CO2, CS2) and their derivatives (eg H2CO3, KSCN), the salt-like and metallic carbides as well as the metal carbonyls all Carbon-free compounds and the chemical elements including carbon and fullerene.

In the context of the present invention particularly suitable organic

Binders comprise plastic dispersions which preferably contain suspensions of finely divided 0.1 to a few μm polymer particles in water. The solids content is preferably 40% to 60%. By choosing the

Monomers, the production conditions and the emulsifiers and

Protective colloids may include binder properties, in particular rheology, storage stability, minimum film forming temperature (MFT), water absorption, chalking, alkali and saponification resistance, and

Pigment binding capacity can be adjusted. Furthermore, in particular for

Bautenschutzfarben the use of alkyd and acrylate resins particularly advantageous. Other preferred binders include vinyl acetate homopolymers, vinyl acetate-acrylate copolymers, vinyl acetate-ethylene copolymers, vinyl acetate-maleate copolymers, vinyl acetate-versatate copolymers, vinyl acetate-versatate-acrylate copolymers, vinyl acetate-vinyl chloride-ethene copolymers, vinyl propionate copolymers. Homopolymers, vinyl propionate-acrylate copolymers, styrene-acrylate copolymers and acrylate homopolymers, copolymers and terpolymers.

The binder content of the emulsion paint can basically be chosen freely. It is preferably in the range of 0.5% by weight to 30.0% by weight, preferably in the range of 0.5% by weight to 17.5% by weight, particularly preferably in the range of 0.5 Wt .-% to 10.0 wt .-%. For particularly preferred

Wall paints, especially for smudge-resistant interior paints, the binder content is in the range of 0.5 wt .-% to 1, 5 wt .-%, each based on the

Total weight of the emulsion paint. For more particularly preferred

Wall paints, especially for wash-resistant interior paints, the binder content is in the range of 2.0 wt .-% to 3.0 wt .-%, each based on the

Total weight of the emulsion paint. For more particularly preferred

Wall paints, especially for wash-resistant interior paints, the binder content is in the range of 4.5 wt .-% to 6.0 wt .-%, each based on the

Total weight of the emulsion paint. For more particularly preferred

Wall paints, especially for scrub resistant interior paints, is the

Binder content in the range of 5.0 wt .-% to 8.0 wt .-%, each based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the binder content is in the range from 5.0% by weight to 7.0% by weight, based in each case on the Total weight of the emulsion paint. For more particularly preferred

Wall paints, especially for scrub resistant interior paints, is the

Binder content in the range of 6.0 wt .-% to 9.0 wt .-%, each based on the total weight of the emulsion paint.

In addition to the water, the emulsion paint according to the invention contains at least spray-dried calcium carbonate particles. The amount of the spray-dried calcium carbonate particles in the dispersion paint can basically be chosen freely. It is preferably in the range from> 0.0% by weight to 50.0% by weight, preferably in the range from 1.0% by weight to 30.0% by weight, particularly preferably in the range from 3, 0% to 25.0% by weight. For particularly preferred

Wall paints, especially for smudge-resistant interior paints, the amount of spray-dried calcium carbonate particles in the range of 4.0 wt .-% to 12.0 wt .-%, each based on the total weight of the emulsion paint. For more particularly preferred wall colors, especially for washable

Interior paints, the amount of the spray-dried calcium carbonate particles is in the range of 6.0 wt .-% to 15.0 wt .-%, each based on the

Total weight of the emulsion paint. For more particularly preferred

Wall paints, especially for wash-resistant interior paints, the amount of spray-dried calcium carbonate particles in the range of 8.0 wt .-% to 24.0 wt .-%, each based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for abrasion-resistant interior paints, the amount of spray-dried calcium carbonate particles is in the range from 8.0% by weight to 18.0% by weight, based in each case on the

Total weight of the emulsion paint. For more particularly preferred

Wall paints, especially for wash-resistant interior paints, the amount of spray-dried calcium carbonate particles in the range of 8.0 wt .-% to 15.0 wt .-%, each based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for abrasion-resistant interior paints, the amount of spray-dried calcium carbonate particles is in the range from 8.0% by weight to 12.0% by weight, based in each case on the

Total weight of the emulsion paint.

According to the invention, "wipe-resistant interior paints" suitably have a wet abrasion resistance according to DIN EN 13300, paragraph 5.4, class 5

(Thickness decrease of the layer> 70 pm at 40 rubbing cycles), preferably according to DIN EN 13300, paragraph 5.4, class 4 (thickness decrease of the layer <70 pm at 40 scrubbing cycles), to "wash-resistant interior paints" according to the invention suitably a wet abrasion resistance according to DIN EN 13300, paragraph 5.4, class 3 (thickness decrease of the layer> 20 mm and <70 mm at 200

According to the invention, "abrasion resistant interior paints" suitably have a wet abrasion resistance according to DIN EN 13300, paragraph 5.4, class 2 (thickness decrease of the layer> 5 mm and <20 mm at 200

Scouring cycles), preferably according to DIN EN 13300, paragraph 5.4, class 1

(Thickness decrease of the layer <5 mm at 200 rubbing cycles), on.

In addition, the emulsion paint according to the invention preferably contains further colorants, in particular pigments and / or dyes. Colorants in this context designate all colorants, in particular inorganic or organic, natural or synthetic colorants. The inorganic colorants include pigments which may also have filler character. The organic colorants include both pigments and dyes. The most important white pigment is titanium dioxide, as it has the highest light scattering power. It is expediently prepared as rutile or as anatase, which according to the invention, however, plays only a minor role. The colorant content of the emulsion paint can basically be chosen freely. It is preferably in the range from 0.0 wt .-% to 30.0 wt .-%, in particular 1, 0 to 25.0 wt .-%, each based on the total weight of the emulsion paint.

A significant advantage of the present invention is the fact that compared with conventional emulsion paints the same color effect can be achieved with less colorants, in particular with less titanium dioxide.

Accordingly, the emulsion paint contains, in each case based on it

Total weight, preferably less than 30.0 wt .-%, preferably less than 25.0 wt .-%, in particular less than 5.0 wt .-% of spray-dried calcium carbonate particles different colorants, in particular titanium dioxide. For particularly preferred wall paints, in particular for wipe-resistant interior paints, the titanium dioxide content is in the range from 1, 0 wt .-% to 2.0 wt .-%, each based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the titanium dioxide content is in the range from 1, 0 wt .-% to 4.0 wt .-%, each based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the titanium dioxide content is in the range from 3.0% by weight to 8.0% by weight, based in each case on the

Total weight of the emulsion paint. For more particularly preferred Wall paints, especially for scrub resistant interior paints, is the

Titanium dioxide content in the range of 8.0 wt .-% to 12.0 wt .-%, each based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the titanium dioxide content is in the range from 10.0% by weight to 15.0% by weight, based in each case on the

Total weight of the emulsion paint. For more particularly preferred

Wall paints, especially for scrub resistant interior paints, is the

Titanium dioxide content in the range of 15.0 wt .-% to 20.0 wt .-%, each based on the total weight of the emulsion paint.

Fillers of various types of grinding and brightness can further increase the volume of the emulsion paint and further improve the technical and optical properties of the emulsion paint. Fillers preferred according to the invention include ground (natural) calcium carbonate (most preferred filler, GCC); precipitated but not spray-dried calcium carbonate (increases brightness and hiding power in paints, reduces the consumption of T1O ₂ );

Diatomaceous earth (amorphous silica with irregular particle shape, matting); Kaolin (aluminum silicate, improves surface smoothness); Mica (potassium aluminum silicate; wet grinding lamellar structure, thus crack-reducing, matting, weatherproof); Talc (magnesium silicate, matt); Barium sulfate (high brightness, increases gloss, chemically inert); as well as quartz

(chemically inert, thixotropic, pyrogenic S1O ₂ ).

The optical properties of the pigments and fillers are preferably determined by the difference in the refractive indices between the surrounding medium and the pigment or filler. The larger this difference, the greater the hiding power. Substances whose refractive indices are greater than 1.7 are commonly referred to as white pigments.

Table: refractive indices

Compared to air, there are greater differences than with binders, so that wherever coating / pigment / air or filler / air interfaces occur, a marked increase in hiding power occurs ("dry-hiding").

Additives are added preferably only in a small amount of 0.2 to 2% in the emulsion paints according to the invention. Preferably, the following additives are used:

- Rheology aids preferably influence the color properties, such.

For example, consistency, viscosity, flow, edge coverage, open time, storage stability, and propensity to splash. Particularly preferred are modified cellulose ethers of very different molecular weights. As further rheology aids, synthetic thickeners, in particular polyacrylate or polyurethane-based, are particularly preferred. In addition, the use of layered silicates, such as LAPONITE as

Thixotropic agents, particularly advantageous (solid color, structural colors).

Wetting and dispersing agents preferably bring about the best possible distribution of the solids in the liquid phase. In addition, one will

Reagglomeration of the solid particles after dispersion as best as possible suppressed. The addition amounts are expediently exactly on the Formulated because an excess of dispersant can adversely affect the washing and abrasion resistance. In particular, polyphosphates and polyacrylates are used.

Film-forming aids preferably enable plastic dispersions of higher minimum film-forming temperature (MFT) by external plasticization

homogeneous film formation. Since the MFT generally increases as a result of the pigmentation, a softening is advantageous even for binders of an MFT below 5 ° C. Low-monomer binders are preferably used which require no additional film formers and thus enable the production of solvent-free and low-odor paints.

Defoamers preferably minimize foaming during the process

Dispersing. The formation of foam bubbles may be e.g. the

Affect surface smoothness of the paint film and reinforce the film tear.

Preservatives preferably prevent infestation of both the paint and the finished paint by bacteria, fungi and algae.

Other preferred additives include wax emulsions, silicone emulsions and hollow spheres (inorganic, organic).

The amount of fillers (spray-dried calcium carbonate, further fillers and additives) in the emulsion paint can basically be chosen freely. It is preferably in the range of> 0.0% by weight to 70.0% by weight, preferably in the range of 5.0 to 66.0% by weight, particularly preferably in the range of 20.0% by weight. % to 66.0% by weight. For particularly preferred wall paints, in particular for wipe-resistant interior paints, the amount of fillers is in the range from 60.0% by weight to 66.0% by weight, in each case based on the total weight of the

Emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the amount of fillers is in the range of 56.0 wt .-% to 62.0 wt .-%, each based on the total weight of

Emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the amount of fillers is in the range from 52.0% by weight to 56.0% by weight, in each case based on the total weight of the

Emulsion paint. For further particularly preferred wall paints, in particular for abrasion-resistant interior paints, the amount of fillers is in the range from 45.0% by weight to 52.0% by weight, in each case based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the amount of fillers is in the range of 40.0 wt .-% to 48.0 wt .-%, each based on the total weight of Emulsion paint. For further particularly preferred wall paints, in particular for abrasion-resistant interior paints, the amount of fillers is in the range from 22.0% by weight to 30.0% by weight, in each case based on the total weight of the emulsion paint.

According to the invention, the emulsion paint contains calcium carbonate particles which have been obtained by spray-drying a precipitated calcium carbonate suspension.

Precipitated Calcium Carbonate (PCC) refers to synthetic calcium carbonate - in contrast to GCC (ground calcium carbonate), "ground (natural) calcium carbonate"). PCC can be made in several ways. Known processes include precipitation with carbon dioxide, the lime-soda process and the Solvay process, in which PCC is a by-product of ammonia production.

The precipitation with carbon dioxide is particularly preferred according to the invention.

Advantageously, quicklime is first quenched to calcium hydroxide (lime) and then fed as a suspension to the reaction vessel. There carbon dioxide is introduced until the calcium hydroxide is completely converted to calcium carbonate. The reaction time can be assessed and controlled by the course of the pH. At the end of the precipitation, the pH of the reaction mixture is preferably less than 9.0, preferably less than 8.0, and is suitably in the range from 6.5 to 7.5.

The precipitation is preferably carried out at a solids content of 10 wt .-% to 20.0 wt .-%. Through the process control, especially on the temperature, the pressure, the time and the concentration, different crystal forms (crystal morphologies) and grain distributions can be generated ("bred").

The rhombohedral or scalenohedral crystal form is preferred.

In the lime-soda process, calcium carbonate is produced as a by-product in the preparation of the caustic alkalis sodium hydroxide and potassium hydroxide.

The specific surface area of the calcium carbonate to be spray-dried is preferably greater than 5 m ² / g, preferably greater than 15 m ² / g, particularly preferably greater than 25 m ² / g, advantageously greater than 35 m ² / g, in particular greater than 40 m ² / g. The mean particle size dso% of the calcium carbonate to be spray-dried is preferably greater than 0.2 μm, preferably greater than 0.5 μm, in particular at least 1.0 μm. On the other hand, it is preferably less than 3.0 μm, preferably less than 2.5 μm, in particular less than 2.0 μm. Within the scope of a particularly preferred embodiment of the present invention, the mean particle size dso% of the calcium carbonate to be spray-dried is in the range of greater than 0.2 μm to less than 3.0 μm, preferably in the range of greater than 0.5 μm to less than 2.5 μm, in particular in the range of at least 1, 0 pm to less than 2.0 pm.

For the purposes of the present invention, the particle size is preferably determined by sedimentation analysis, conveniently using the Sedigraph 5100 (Micromeritics GmbH).

According to the invention, the calcium carbonate to be spray-dried is preferably calcitic calcium carbonate. Within the scope of a particularly preferred

Embodiment of the present invention is the proportion of crystalline

Calcium carbonate, in particular of calcitic calcium carbonate,

comparatively high and preferably greater than 10% by weight, preferably greater than 25% by weight, advantageously greater than 50% by weight, particularly preferably greater than 70% by weight, very particularly preferably greater than 80% by weight, in particular greater than 90% by weight .-%, each based on the total weight of calcium carbonate.

X-ray diffraction with an internal standard, preferably aluminum oxide, in conjunction with a Rietveld refinement has proved to be particularly suitable for determining the crystalline fractions.

Furthermore, for the purposes of the present invention, scalenohedral and rhombohedral, in particular rhombohedral, calcium carbonate particles have proven particularly useful.

For more details on the terms of crystal morphology is on the

Specialist literature, in particular on Römpp-Lexikon Chemie / ed. Jürgen Falbe; Manfred Regitz edited by Eckard Amelingmeier; Stuttgart, New York;

Thieme; Volume 3; 10th edition (1997); Keyword "crystal morphology" and the references given there referenced. The spray-drying of the suspension of the precipitated calcium carbonate particles can be carried out in a manner known per se. First, preferably the

spray-drying suspension containing the desired components, in particular the precipitated calcium carbonate particles. Preferably, the suspension comprises, based on its total weight, at least 5.0% by weight, preferably at least 10.0% by weight, in particular at least 15.0% by weight, of precipitated calcium carbonate particles. Furthermore, the suspension comprises

preferably at least water. The water content is the

Suspension, based on their total weight, preferably at least 65.0 wt .-%, preferably at least 75.0 wt .-%, in particular at least 85% by weight. Possibly. For example, the suspension may contain other additives whose content is preferably as low as possible. The content of further additives, based on the total weight of the suspension, is therefore preferably less than 25.0% by weight, preferably less than 10.0% by weight, more preferably less than 5.0% by weight, advantageously less than 1, 0 wt .-%, in particular less than 0.5% by weight.

Surprisingly, it has been found according to the invention that spray-dried PCC binder aggregates have the properties of emulsion paints,

especially the sheen, adversely affect the wet abrasion of the resulting paint. Accordingly, the smallest possible proportion by weight of inorganic binder, based on PCC, is sought in the spray-to-be-dried suspension, which is advantageously less than 2.4% by weight, preferably less than 2.0% by weight, more preferably less than 1.0% by weight. %, in particular less than 0.5 wt .-% is. In a very particularly preferred variant of the present invention, the spray-dried suspension contains no inorganic binder.

Furthermore, the smallest possible proportion by weight of organic binder, based on PCC, is sought in the spray-to-be-dried suspension, which is advantageously less than 20.0% by weight, preferably less than 15.0% by weight, more preferably less than 10.0% by weight. %, in particular less than 5.0 wt .-% is. Within the scope of a most preferred variant of the present invention

Invention, the spray-drying suspension contains no inorganic

Binder.

By means of a pressure atomizer (also single-fluid nozzle, preferably 50 to 250 bar), a pneumatic atomizer (also two-fluid nozzle, preferably 1 to 10 bar) or a rotary atomizer (preferably 4000 to 50,000 1 / min), the suspension to be dried is preferably converted into a spray. This enormously increases the total surface area of the suspension.

The spray is preferably introduced into a stream of hot gas, whereby due to the large surface in a very short time the liquid dries convectively to a fine powder. The hot gas is preferably air. The inlet temperature of the hot gas is preferably in the range of 125 ° C to 500 ° C, preferably in the range of 2O0 ° C to 350 ° C, in particular in the range of 250 ° C to 300 ° C. The outlet temperature of the hot gas is preferably in the range of 25 ° C to 300 ° C, preferably in the range of 50 ° C to 200 ° C, in particular in the range of 100 ° C to 150 ° C. The spray concentration of the PCC is preferably selected in the range of 1% to 40%, preferably in the range of 5% to 25%, in particular in the range of 7.5% to 15%.

The resulting powdered material to be dried is expediently separated from the air stream by a cyclone separator. The spray dryer is preferably operated continuously.

According to the invention, the spray-dried calcium carbonate particles preferably have a ratio of BET specific surface area to average

Particle size dso% greater than 6 m ² / (gm), preferably greater than 7 m ² / (gm),

expediently greater than 8 m ² / (gmm), advantageously greater than 10 m ² / (gm), even more preferably greater than 20 m ² / (gm), very particularly preferably greater than 40 m ² / (gm), in particular greater than 50 m ² / (gmm). On the other hand, the spray-dried calcium carbonate particles preferably have a ratio BET surface area to average particle size dso% less than 200 m ² / (gmm), preferably less than 150 m ² / (g pm), advantageously less than 125 m ² / (gmm), conveniently less than 112 m ² / (gmm), even more preferably less than 110 m ² / (gm), most preferably less than 100 m ² / (gm), in particular less than 95 m ² / (gm).

The pigment volume concentration of the dispersion paint PVK according to the invention

can basically be chosen freely and adapted to the specific application. Preferably, the PVK is in the range of 25% to 99%, preferably in the range of 40% to 99%, in particular in the range of 62% to 98%.

For particularly preferred wall paints, in particular for wipe-resistant interior paints, the PVC is in the range from 93.0% by weight to 98.0% by weight, in each case based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the PVC is in the range from 80.0% by weight to 92.0% by weight, in each case based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the PVC is in the range from 78.0% by weight to 83.0% by weight, in each case based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for abrasion-resistant interior paints, the PVC is in the range from 74.0% by weight to 76.0% by weight, in each case based on the total weight of the emulsion paint. For further particularly preferred wall paints, in particular for wash-resistant interior paints, the PVK is in the range from 68.0% by weight to 72.0% by weight, in each case based on the

Total weight of the emulsion paint. For more particularly preferred

Wall paints, especially for abrasion resistant interior paints, PVK is in the range of 62.0 wt .-% to 70.0 wt .-%, each based on the

Total weight of the emulsion paint.

The paint obtained by applying the emulsion paint has a comparatively low sheen (gloss at 85 °). The sheen is preferably less than 10, preferably less than 5, particularly preferably less than 4,

suitably less than 3.5, favorably less than 3.0, even more preferably less than 2.5, in particular less than 2.0.

In addition, the abrasiveness and wet abrasion of the paint obtainable by applying the emulsion paint is very low. The wet abrasion is

preferably less than 70 pm at 40 rubbing cycles (this corresponds to a

Wet abrasion resistance in accordance with DIN EN 13300, paragraph 5.4, class 4), preferably less than 70 pm at 200 rubbing cycles (this corresponds to a

Wet abrasion resistance according to DIN EN 13300, paragraph 5.4, class 3),

expediently less than 34 μm for 200 scrubbing cycles, preferably less than 30 μm for 200 scrubbing cycles, favorably less than 25 μm for 200 scrubbing cycles, very particularly preferably less than 20 μm for 200 scrubbing cycles (this corresponds to a wet scrub resistance according to DIN EN 13300, Paragraph 5.4, Class 2), more preferably less than 5 pm at 200 rubbing cycles (this corresponds to a wet abrasion resistance according to DIN EN 13300, paragraph 5.4, class 1).

Further, the paint obtainable by applying the emulsion paint has a sufficient hiding power (contrast ratio, KV). The hiding power is preferably at least 92.0%, preferably greater than 95.0%, particularly preferably greater than 97.0%, very particularly preferably greater than 97.3%, in particular greater than 97.5%.

The white value R 457 of the powder obtainable by application of the emulsion paint

Paint is preferably greater than 89.0, preferably greater than 90.0, in particular greater than 90.3.

Hereinafter, the present invention by examples and

Comparative examples further illustrated, without thereby a

Restriction of the inventive concept should take place.

1. Production of calcium carbonate by precipitation

Lime milk is placed in an intensively stirred reactor, added tartaric acid and continuously added C02-containing gas. After 1.4 hours, the pH in the reaction vessel drops to 7. The C02 introduction is continued for another 0.1 hours. The suspension thus obtained is fed to the spray dryer according to the invention and dried.

A portion of the resulting suspension is oven dried at 130 ° C for the Comparative Examples and ground or concentrated by filtration to a slurry.

Further details of the preparation conditions are given in Table 1

summarized. Table 1

2. Grinding of the spray-dried calcium carbonate

Part of the product from step 1 is ground.

Table 2

Table 4 shows the materials investigated here. The crystal modification was determined by X-ray diffraction. The BET specific surface area was measured according to DIN-ISO 9277. The particle size d50% was determined by Sedigraph. 3. Preparation of the emulsion paints

Equipment:

• 1 L stainless steel cup (d ~ 9cm)

• dispersing disk (d ~ 7cm)

• Dissolver Pendraulik LD50

• Desiccator with stirrer and vacuum pump

Table 3: Recipe:

¹ : 59-61% solids (130 ° C, 30 min)

Execution:

1. Weigh out water and thickener and allow to swell for 3 min

2. Add ammonia and wetting agent and disperse for 3 min at 1865 rpm (step 2)

3. Weigh in T1O2 and add with stirring

, Weigh PCC and add with stirring

5. Weigh GCC and add with stirring

, Disperse for 5 minutes at 2800 rpm (step 3)

7. Place the stainless steel cup on the balance and weigh in the binder, defoamer and biocide 8. Stir everything with the spatula, then disperse for 2 min at 1865 rpm (step 2)

For degassing

9. Put the stainless steel cup in the desiccator

10. Close desiccator, set stirrer to 50 revolutions / min

11. Switch on the vacuum pump and let it stir / degas for 10 min

12. Fill emulsion paint and allow to rest for at least one day

4. Testing of emulsion paints

4.1 Apply the colors

Equipment:

• Electromotive film applicator (Erichsen, Coatmaster 509 / MC-I)

• Aufziehrakel (Erichsen, model 288, 200mm)

• Films Leneta, Fa. Erichsen, type 255, black, matt

• Contrast card Leneta, form 14H

Execution:

1. Switch on film applicator and vacuum pump

2. Place the film / card on the film applicator

3. Place the squeegee (200mm) on the foil / card

4. Stir the color and place directly in front of the squeegee

5. Start film applicator (coating speed: 12.5 mm / s)

- for wet abrasion: films Leneta, Fa. Erichsen, type 255, black, matt; Dry films in oven at 50 ° C overnight, then allow to acclimatize for one hour at room temperature

- For hiding power: contrast card Leneta, form 14H coat;

Allow contrast to dry overnight at RT

4.2 Determination of wet abrasion

The determination of the wet abrasion resistance is carried out according to DIN EN ISO 11998. The division into classes, comparable to the criteria "washable", "abrasion resistant" and "cleaning resistant" according to DIN 53778-2, is in the European Standard for the classification of interior paints, DIN EN 13300, described.

To test the wet abrasion resistance, the paint to be tested is applied to a film with a film applicator of a defined thickness. After drying, the coated film is subjected to 200 rubbing cycles in a scrub tester and the layer thickness loss is calculated in microns. Equipment:

• Erichsen Washability and Abrasion Tester (Model 494)

• Scouring fleece Scotch-Brite 3M, Nr.07448

Washing liquid: (2.5 g / L sodium n-dodecylbenzenesulfonate in E water)

• Foil coated with the prepared emulsion paint Leneta, Fa.

Erichsen, type 255, black, matt

• Micrometer Digimatic, Mitutoyo

execution

1. Cut the foil into three strips, dimensions: width 70 mm, length 430 mm

2. Weigh on analytical balance

3. Place sample foil on the glass of the scrub tester

4. Clamp with screw terminals

5. Spread the washing liquid on the coating with a soft brush and allow the liquid to act on the coating for 60 seconds

6. Saturate scouring fleece with 4 g washing liquid

7. Place scouring fleece on the intended holder and in contact with the holder

Apply coating so that the unprinted side of the fleece is in contact with the coating during the test.

8. Start scouring tester - 200 cycles.

9. Remove excess scrubbing liquid applied with the brush within the first scrub cycle

10. Remove the sample foil from the instrument and from the glass, rinse immediately with tap water;

11. Dab gently with a cloth; allow to dry to constant mass, 50 ° C overnight in a drying oven

12. Weigh on analytical balance

13. The mass loss is calculated according to:

Mass loss = mass before rubbing - mass after scrubbing.3 Determination of dry film density

1. From an uncoated sample foil a piece of 100 mm * 100 mm is cut by means of a template and the mass is determined exactly to 1 mg.

, The thickness of the uncoated sample sheet is determined to be accurate to 1pm. From a coated sample foil, a piece of 100 mm ^× 100 mm is produced by means of a template and the mass is determined exactly to 1 mg.

, The thickness of the coated sample film is determined to be accurate to 1 pm 5. The dry film density is determined according to the following formula:

p dry film density

m2 mass (g) of uncoated specimens

mx mass (g) of the coated specimens

dl Thickness (mm) of uncoated specimens

dx thickness (mm) of the coated specimens

A2 area (mm ² ) of the specimens

The layer thickness loss is calculated:

Wet abrasion (mm) - mass loss (mg) / dry film density (mg / gm)

4.4 Determination Sheen / gloss at 85 °

Equipment:

• BYK, micro TRI gloss

• Coated with prepared emulsion paint and overnight

Room temperature dried contrast card (Leneta, Form 14H)

execution

1. Switch on the device and wait for the autodiagnosis (if necessary calibrate)

2. Device on the coated contrast card points, start measurement, read off values of 85 °

4.5 Opacity or opacity, measured as the contrast ratio

Equipment:

• Spectrophotometer (Minolta CM-3610d)

• Contrast cards coated with prepared emulsion paint and dried at room temperature overnight (Leneta, Form 14H) execution

1. Place the white part of the card in four different places under the unit and measure the RYw value.

2. Place the black section of the card in four different places below the unit and measure the RYb value.

3. The values are averaged each time and the contrast ratio is calculated according to the following formula:

Contrast ratio (%) = RYb / RYw * 100

Claims

claims:

1. emulsion paint comprising at least water and spray-dried

Calcium carbonate particles, characterized in that the

Calcium carbonate particles were obtained by spray-drying a suspension of precipitated calcium carbonate particles.

2. emulsion paint according to claim 1, characterized in that the

Calcium carbonate particles were obtained by spray drying a suspension of precipitated calcium carbonate particles having a weight fraction of inorganic binder, based on PCC, less than 2.4 wt .-%.

3. emulsion paint according to claim 1 or 2, characterized in that the calcium carbonate particles were obtained by spray drying a suspension of precipitated calcium carbonate particles having a specific surface area (BET) greater than 5 m ² / g and an average particle size d50 less than 3.0 pm.

4. emulsion paint according to at least one of the preceding claims, characterized in that the calcium carbonate particles by

Spray drying of a suspension of precipitated calcium carbonate particles were obtained, wherein

Transferring an aqueous suspension of precipitated calcium carbonate particles into a spray and

The spray is introduced into a stream of hot gas and dried to a powder, wherein the inlet temperature of the hot gas in the range of 125 ° C to 500 ° C and the outlet temperature of the hot gas in the range of 25 ° C to 300 ° C.

5. emulsion paint according to at least one of the preceding claims, characterized in that the spray-dried calcium carbonate particles have a ratio of BET specific surface area to average

Particle size d50% greater than 6 m ² / (gmm) have.

6. emulsion paint according to at least one of the preceding claims, characterized in that the dispersion paint, based on it

Total weight,> 0.0 wt .-% to 50.0 wt .-% spray-dried

Contains calcium carbonate particles.

7. emulsion paint according to at least one of the preceding claims, characterized in that the emulsion paint, based on its total weight, 1, 0 wt .-% to 60.0 wt .-% of at least one binder.

8. emulsion paint according to at least one of the preceding claims, characterized in that the pigment volume concentration of the dispersion paint in the range of 25% to 99%.

9. emulsion paint according to at least one of the preceding claims, characterized in that the emulsion paint, based on it

Total weight, at least 10.0 wt .-% water.

10. emulsion paint according to at least one of the preceding claims, characterized in that the dispersion paint, based on it

Total weight, less than 30.0% by weight of spray dried

Calcium carbonate particles containing various colorants.

11. emulsion paint according to at least one of the preceding claims, characterized in that the dispersion paint, based on it

Total weight,> 0.0 wt .-% to 70.0 wt .-% of at least one filler.

12. emulsion paint according to at least one of the preceding claims, characterized in that the dispersion paint additionally contains precipitated, but not spray-dried calcium carbonate.

13. emulsion paint according to at least one of the preceding claims, characterized in that a coat obtainable by applying the emulsion paint has a sheen less than 10.

14. emulsion paint according to at least one of the preceding claims, characterized in that a coat obtainable by applying the emulsion paint has a wet abrasion less than 70 pm at 40 scrubbing cycles.

15. emulsion paint according to at least one of the preceding claims, characterized in that a coat obtainable by applying the emulsion paint has a Konstrastverhältnis of at least 92.0%.

16. Use of an emulsion paint after at least one of

preceding claims as wall paint.